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Sample records for aerodynamic design procedure

  1. A Rapid Aerodynamic Design Procedure Based on Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan

    2001-01-01

    An aerodynamic design procedure that uses neural networks to model the functional behavior of the objective function in design space has been developed. This method incorporates several improvements to an earlier method that employed a strategy called parameter-based partitioning of the design space in order to reduce the computational costs associated with design optimization. As with the earlier method, the current method uses a sequence of response surfaces to traverse the design space in search of the optimal solution. The new method yields significant reductions in computational costs by using composite response surfaces with better generalization capabilities and by exploiting synergies between the optimization method and the simulation codes used to generate the training data. These reductions in design optimization costs are demonstrated for a turbine airfoil design study where a generic shape is evolved into an optimal airfoil.

  2. Study of Aerodynamic Design Procedure of a Large-Scale Aircraft Noise Suppression Facility

    NASA Astrophysics Data System (ADS)

    Kawai, Masafumi; Nagai, Kiyoyuki; Aso, Shigeru

    The aerodynamic design procedure of a large-scale aircraft noise suppression facility has been developed. Flow quality required for the engine inlet flow has been determined through basic experiment. Aerodynamic design of the facility has been performed by using wind tunnel experiment and CFD. Important relationship between the length of the facility and the inlet flow quality has been found. The operational envelope of the designed facility has been estimated. Then, the aerodynamic characteristics of an actual large-scale aircraft noise suppression facility, constructed based on the new design procedure, have been measured. Obtained flow field showed good agreement with CFD results, and the effectiveness of the design procedure based on CFD and wind tunnel experiment has been confirmed. The engine operations were satisfactory under various wind conditions. Furthermore, the data under commercial operations thereafter have been collected and analyzed. As the result, the aerodynamic design procedure has been validated.

  3. Aerodynamic design using numerical optimization

    NASA Technical Reports Server (NTRS)

    Murman, E. M.; Chapman, G. T.

    1983-01-01

    The procedure of using numerical optimization methods coupled with computational fluid dynamic (CFD) codes for the development of an aerodynamic design is examined. Several approaches that replace wind tunnel tests, develop pressure distributions and derive designs, or fulfill preset design criteria are presented. The method of Aerodynamic Design by Numerical Optimization (ADNO) is described and illustrated with examples.

  4. Aerodynamic Design Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan; Madavan, Nateri K.

    2003-01-01

    The design of aerodynamic components of aircraft, such as wings or engines, involves a process of obtaining the most optimal component shape that can deliver the desired level of component performance, subject to various constraints, e.g., total weight or cost, that the component must satisfy. Aerodynamic design can thus be formulated as an optimization problem that involves the minimization of an objective function subject to constraints. A new aerodynamic design optimization procedure based on neural networks and response surface methodology (RSM) incorporates the advantages of both traditional RSM and neural networks. The procedure uses a strategy, denoted parameter-based partitioning of the design space, to construct a sequence of response surfaces based on both neural networks and polynomial fits to traverse the design space in search of the optimal solution. Some desirable characteristics of the new design optimization procedure include the ability to handle a variety of design objectives, easily impose constraints, and incorporate design guidelines and rules of thumb. It provides an infrastructure for variable fidelity analysis and reduces the cost of computation by using less-expensive, lower fidelity simulations in the early stages of the design evolution. The initial or starting design can be far from optimal. The procedure is easy and economical to use in large-dimensional design space and can be used to perform design tradeoff studies rapidly. Designs involving multiple disciplines can also be optimized. Some practical applications of the design procedure that have demonstrated some of its capabilities include the inverse design of an optimal turbine airfoil starting from a generic shape and the redesign of transonic turbines to improve their unsteady aerodynamic characteristics.

  5. Aerodynamic design via control theory

    NASA Technical Reports Server (NTRS)

    Jameson, Antony

    1988-01-01

    The question of how to modify aerodynamic design in order to improve performance is addressed. Representative examples are given to demonstrate the computational feasibility of using control theory for such a purpose. An introduction and historical survey of the subject is included.

  6. Integrated structural-aerodynamic design optimization

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Kao, P. J.; Grossman, B.; Polen, D.; Sobieszczanski-Sobieski, J.

    1988-01-01

    This paper focuses on the processes of simultaneous aerodynamic and structural wing design as a prototype for design integration, with emphasis on the major difficulty associated with multidisciplinary design optimization processes, their enormous computational costs. Methods are presented for reducing this computational burden through the development of efficient methods for cross-sensitivity calculations and the implementation of approximate optimization procedures. Utilizing a modular sensitivity analysis approach, it is shown that the sensitivities can be computed without the expensive calculation of the derivatives of the aerodynamic influence coefficient matrix, and the derivatives of the structural flexibility matrix. The same process is used to efficiently evaluate the sensitivities of the wing divergence constraint, which should be particularly useful, not only in problems of complete integrated aircraft design, but also in aeroelastic tailoring applications.

  7. Computational aerodynamics applications to transport aircraft design

    NASA Technical Reports Server (NTRS)

    Henne, P. A.

    1983-01-01

    Examples are cited in assessing the effect that computational aerodynamics has had on the design of transport aircraft. The application of computational potential flow methods to wing design and to high-lift system design is discussed. The benefits offered by computational aerodynamics in reducing design cost, time, and risk are shown to be substantial.These aerodynamic methods have proved to be particularly effective in exposing inferior or poor aerodynamic designs. Particular attention is given to wing design, where the results have been dramatic.

  8. Review of aerodynamic design in the Netherlands

    NASA Technical Reports Server (NTRS)

    Labrujere, Th. E.

    1991-01-01

    Aerodynamic design activities in the Netherlands, which take place mainly at Fokker, the National Aerospace Laboratory (NLR), and Delft University of Technology (TUD), are discussed. The survey concentrates on the development of the Fokker 100 wing, glider design at TUD, and research at NLR in the field of aerodynamic design. Results are shown to illustrate these activities.

  9. Aerodynamic design on high-speed trains

    NASA Astrophysics Data System (ADS)

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-01-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  10. Aerodynamic design on high-speed trains

    NASA Astrophysics Data System (ADS)

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-04-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  11. Aerodynamic design of electric and hybrid vehicles: A guidebook

    NASA Technical Reports Server (NTRS)

    Kurtz, D. W.

    1980-01-01

    A typical present-day subcompact electric hybrid vehicle (EHV), operating on an SAE J227a D driving cycle, consumes up to 35% of its road energy requirement overcoming aerodynamic resistance. The application of an integrated system design approach, where drag reduction is an important design parameter, can increase the cycle range by more than 15%. This guidebook highlights a logic strategy for including aerodynamic drag reduction in the design of electric and hybrid vehicles to the degree appropriate to the mission requirements. Backup information and procedures are included in order to implement the strategy. Elements of the procedure are based on extensive wind tunnel tests involving generic subscale models and full-scale prototype EHVs. The user need not have any previous aerodynamic background. By necessity, the procedure utilizes many generic approximations and assumptions resulting in various levels of uncertainty. Dealing with these uncertainties, however, is a key feature of the strategy.

  12. Aerodynamics Research Revolutionizes Truck Design

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During the 1970s and 1980s, researchers at Dryden Flight Research Center conducted numerous tests to refine the shape of trucks to reduce aerodynamic drag and improved efficiency. During the 1980s and 1990s, a team based at Langley Research Center explored controlling drag and the flow of air around a moving body. Aeroserve Technologies Ltd., of Ottawa, Canada, with its subsidiary, Airtab LLC, in Loveland, Colorado, applied the research from Dryden and Langley to the development of the Airtab vortex generator. Airtabs create two counter-rotating vortices to reduce wind resistance and aerodynamic drag of trucks, trailers, recreational vehicles, and many other vehicles.

  13. Aerodynamic design of a free power turbine for a 75 KW gas turbine automotive engine

    NASA Technical Reports Server (NTRS)

    Kofskey, M. G.; Katsanis, T.; Schumann, L. F.

    1975-01-01

    A single stage axial-flow turbine having a tip diameter of 15.41 centimeters was designed. The design specifications are given and the aerodynamic design procedure is described. The design includes the transition duct and the turbine exit diffuser. The aerodynamic information includes typical results of a parametric study, velocity diagrams, blade surface and wall velocities, and blade profile and wall coordinates.

  14. Efficient optimization of integrated aerodynamic-structural design

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Grossman, B.; Eppard, W. M.; Kao, P. J.; Polen, D. M.

    1989-01-01

    Techniques for reducing the computational complexity of multidisciplinary design optimization (DO) of aerodynamic structures are described and demonstrated. The basic principles of aerodynamic and structural DO are reviewed; the formulation of the combined DO problem is outlined; and particular attention is given to (1) the application of perturbation methods to cross-sensitivity computations and (2) numerical approximation procedures. Trial DOs of a simple sailplane design are presented in tables and graphs and discussed in detail. The IBM 3090 CPU time for the entire integrated DO was reduced from an estimated 10 h to about 6 min.

  15. AWT aerodynamic design status. [Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Davis, Milt W.

    1984-01-01

    The aerodynamic design of the NASA Altitude Wind Tunnel is presented in viewgraph format. The main topics covered are: analysis of a plenum evacuation system; airline definition and pressure loss code development; contraction geometry and code analysis; and design of the two stage fan. Flow characteristics such as pressure ratio, mach number distribution, adiabatic efficiency, and losses are shown.

  16. Aerodynamic Design of Axial Flow Compressors

    NASA Technical Reports Server (NTRS)

    Bullock, R. O. (Editor); Johnsen, I. A.

    1965-01-01

    An overview of 'Aerodynamic systems design of axial flow compressors' is presented. Numerous chapters cover topics such as compressor design, ptotential and viscous flow in two dimensional cascades, compressor stall and blade vibration, and compressor flow theory. Theoretical aspects of flow are also covered.

  17. Aerodynamic optimization by simultaneously updating flow variables and design parameters

    NASA Technical Reports Server (NTRS)

    Rizk, M. H.

    1990-01-01

    The application of conventional optimization schemes to aerodynamic design problems leads to inner-outer iterative procedures that are very costly. An alternative approach is presented based on the idea of updating the flow variable iterative solutions and the design parameter iterative solutions simultaneously. Two schemes based on this idea are applied to problems of correcting wind tunnel wall interference and optimizing advanced propeller designs. The first of these schemes is applicable to a limited class of two-design-parameter problems with an equality constraint. It requires the computation of a single flow solution. The second scheme is suitable for application to general aerodynamic problems. It requires the computation of several flow solutions in parallel. In both schemes, the design parameters are updated as the iterative flow solutions evolve. Computations are performed to test the schemes' efficiency, accuracy, and sensitivity to variations in the computational parameters.

  18. Formulation for Simultaneous Aerodynamic Analysis and Design Optimization

    NASA Technical Reports Server (NTRS)

    Hou, G. W.; Taylor, A. C., III; Mani, S. V.; Newman, P. A.

    1993-01-01

    An efficient approach for simultaneous aerodynamic analysis and design optimization is presented. This approach does not require the performance of many flow analyses at each design optimization step, which can be an expensive procedure. Thus, this approach brings us one step closer to meeting the challenge of incorporating computational fluid dynamic codes into gradient-based optimization techniques for aerodynamic design. An adjoint-variable method is introduced to nullify the effect of the increased number of design variables in the problem formulation. The method has been successfully tested on one-dimensional nozzle flow problems, including a sample problem with a normal shock. Implementations of the above algorithm are also presented that incorporate Newton iterations to secure a high-quality flow solution at the end of the design process. Implementations with iterative flow solvers are possible and will be required for large, multidimensional flow problems.

  19. Aerodynamic design lowers truck fuel consumption

    NASA Technical Reports Server (NTRS)

    Steers, L.

    1978-01-01

    Energy-saving concepts in truck design are emerging from developing new shapes with improved aerodynamic flow properties that can reduce air-drag coefficient of conventional tractor-trailers without requiring severe design changes or compromising load-carrying capability. Improvements are expected to decrease somewhat with increased wind velocities and would be affected by factors such as terrain, driving techniques, and mechanical condition.

  20. Aerodynamic optimum design of transonic turbine cascades using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Li, Jun; Feng, Zhenping; Chang, Jianzhong; Shen, Zuda

    1997-06-01

    This paper presents an aerodynamic optimum design method for transonic turbine cascades based on the Genetic Algorithms coupled to the inviscid flow Euler solver and the boundary-layer calculation. The Genetic Algorithms control the evolution of a population of cascades towards an optimum design. The fitness value of each string is evaluated using the flow solver. The design procedure has been developed and the behavior of the genetic algorithms has been tested. The objective functions of the design examples are the minimum mean-square deviation between the aimed pressure and computed pressure and the minimum amount of user expertise.

  1. Integrated aerodynamic-structural-control wing design

    NASA Technical Reports Server (NTRS)

    Rais-Rohani, M.; Haftka, R. T.; Grossman, B.; Unger, E. R.

    1992-01-01

    The aerodynamic-structural-control design of a forward-swept composite wing for a high subsonic transport aircraft is considered. The structural analysis is based on a finite-element method. The aerodynamic calculations are based on a vortex-lattice method, and the control calculations are based on an output feedback control. The wing is designed for minimum weight subject to structural, performance/aerodynamic and control constraints. Efficient methods are used to calculate the control-deflection and control-effectiveness sensitivities which appear as second-order derivatives in the control constraint equations. To suppress the aeroelastic divergence of the forward-swept wing, and to reduce the gross weight of the design aircraft, two separate cases are studied: (1) combined application of aeroelastic tailoring and active controls; and (2) aeroelastic tailoring alone. The results of this study indicated that, for this particular example, aeroelastic tailoring is sufficient for suppressing the aeroelastic divergence, and the use of active controls was not necessary.

  2. Aerodynamic Design Opportunities for Future Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.; Flamm, Jeffrey D.

    2002-01-01

    A discussion of a diverse set of aerodynamic opportunities to improve the aerodynamic performance of future supersonic aircraft has been presented and discussed. These ideas are offered to the community in a hope that future supersonic vehicle development activities will not be hindered by past efforts. A number of nonlinear flow based drag reduction technologies are presented and discussed. The subject technologies are related to the areas of interference flows, vehicle concepts, vortex flows, wing design, advanced control effectors, and planform design. The authors also discussed the importance of improving the aerodynamic design environment to allow creativity and knowledge greater influence. A review of all of the data presented show that pressure drag reductions on the order of 50 to 60 counts are achievable, compared to a conventional supersonic cruise vehicle, with the application of several of the discussed technologies. These drag reductions would correlate to a 30 to 40% increase in cruise L/D (lift-to-drag ratio) for a commercial supersonic transport.

  3. Integrated aerodynamic/structural design of a sailplane wing

    NASA Technical Reports Server (NTRS)

    Grossman, B.; Gurdal, Z.; Haftka, R. T.; Strauch, G. J.; Eppard, W. M.

    1986-01-01

    Using lifting-line theory and beam analysis, the geometry (planiform and twist) and composite material structural sizes (skin thickness, spar cap, and web thickness) were designed for a sailplane wing, subject to both structural and aerodynamic constraints. For all elements, the integrated design (simultaneously designing the aerodynamics and the structure) was superior in terms of performance and weight to the sequential design (where the aerodynamic geometry is designed to maximize the performance, following which a structural/aeroelastic design minimizes the weight). Integrated designs produced less rigid, higher aspect ratio wings with favorable aerodynamic/structural interactions.

  4. Aerodynamic design trends for commercial aircraft

    NASA Technical Reports Server (NTRS)

    Hilbig, R.; Koerner, H.

    1986-01-01

    Recent research on advanced-configuration commercial aircraft at DFVLR is surveyed, with a focus on aerodynamic approaches to improved performance. Topics examined include transonic wings with variable camber or shock/boundary-layer control, wings with reduced friction drag or laminarized flow, prop-fan propulsion, and unusual configurations or wing profiles. Drawings, diagrams, and graphs of predicted performance are provided, and the need for extensive development efforts using powerful computer facilities, high-speed and low-speed wind tunnels, and flight tests of models (mounted on specially designed carrier aircraft) is indicated.

  5. Integrated aerodynamic-structural design of a transport wing

    NASA Technical Reports Server (NTRS)

    Grossman, B.; Haftka, R. T.; Kao, P.-J.; Polen, D. M.; Rais-Rohani, M.; Sobieszczanski-Sobieski, J.

    1989-01-01

    The integrated aerodynamic-structural design of a subsonic transport wing for minimum weight subject to required range is formulated and solved. The problem requires large computational resources, and two methods are used to alleviate the computational burden. First, a modular sensitivity method that permits the usage of black-box disciplinary software packages, is used to reduce the cost of sensitivity derivatives. In particular, it is shown that derivatives of the aeroelastic response and divergence speed can be calculated without the costly computation of derivatives of aerodynamic influence coefficient and structural stiffness matrices. A sequential approximate optimization is used to further reduce computational cost. The optimization procedure is shown to require a relatively small number of analysis and sensitivity calculations.

  6. Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design

    NASA Technical Reports Server (NTRS)

    Adamczyk, John J.

    1999-01-01

    This paper summarizes the state of 3D CFD based models of the time average flow field within axial flow multistage turbomachines. Emphasis is placed on models which are compatible with the industrial design environment and those models which offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models which are free of aerodynamic input from semi-empirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures which can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines which help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time average flow models.

  7. Recent Improvements in Aerodynamic Design Optimization on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Anderson, W. Kyle

    2000-01-01

    Recent improvements in an unstructured-grid method for large-scale aerodynamic design are presented. Previous work had shown such computations to be prohibitively long in a sequential processing environment. Also, robust adjoint solutions and mesh movement procedures were difficult to realize, particularly for viscous flows. To overcome these limiting factors, a set of design codes based on a discrete adjoint method is extended to a multiprocessor environment using a shared memory approach. A nearly linear speedup is demonstrated, and the consistency of the linearizations is shown to remain valid. The full linearization of the residual is used to precondition the adjoint system, and a significantly improved convergence rate is obtained. A new mesh movement algorithm is implemented and several advantages over an existing technique are presented. Several design cases are shown for turbulent flows in two and three dimensions.

  8. Integrated aerodynamic-structural design of a forward-swept transport wing

    NASA Technical Reports Server (NTRS)

    Haftka, Raphael T.; Grossman, Bernard; Kao, Pi-Jen; Polen, David M.; Sobieszczanski-Sobieski, Jaroslaw

    1989-01-01

    The introduction of composite materials is having a profound effect on aircraft design. Since these materials permit the designer to tailor material properties to improve structural, aerodynamic and acoustic performance, they require an integrated multidisciplinary design process. Futhermore, because of the complexity of the design process, numerical optimization methods are required. The utilization of integrated multidisciplinary design procedures for improving aircraft design is not currently feasible because of software coordination problems and the enormous computational burden. Even with the expected rapid growth of supercomputers and parallel architectures, these tasks will not be practical without the development of efficient methods for cross-disciplinary sensitivities and efficient optimization procedures. The present research is part of an on-going effort which is focused on the processes of simultaneous aerodynamic and structural wing design as a prototype for design integration. A sequence of integrated wing design procedures has been developed in order to investigate various aspects of the design process.

  9. Global Design Optimization for Aerodynamics and Rocket Propulsion Components

    NASA Technical Reports Server (NTRS)

    Shyy, Wei; Papila, Nilay; Vaidyanathan, Rajkumar; Tucker, Kevin; Turner, James E. (Technical Monitor)

    2000-01-01

    Modern computational and experimental tools for aerodynamics and propulsion applications have matured to a stage where they can provide substantial insight into engineering processes involving fluid flows, and can be fruitfully utilized to help improve the design of practical devices. In particular, rapid and continuous development in aerospace engineering demands that new design concepts be regularly proposed to meet goals for increased performance, robustness and safety while concurrently decreasing cost. To date, the majority of the effort in design optimization of fluid dynamics has relied on gradient-based search algorithms. Global optimization methods can utilize the information collected from various sources and by different tools. These methods offer multi-criterion optimization, handle the existence of multiple design points and trade-offs via insight into the entire design space, can easily perform tasks in parallel, and are often effective in filtering the noise intrinsic to numerical and experimental data. However, a successful application of the global optimization method needs to address issues related to data requirements with an increase in the number of design variables, and methods for predicting the model performance. In this article, we review recent progress made in establishing suitable global optimization techniques employing neural network and polynomial-based response surface methodologies. Issues addressed include techniques for construction of the response surface, design of experiment techniques for supplying information in an economical manner, optimization procedures and multi-level techniques, and assessment of relative performance between polynomials and neural networks. Examples drawn from wing aerodynamics, turbulent diffuser flows, gas-gas injectors, and supersonic turbines are employed to help demonstrate the issues involved in an engineering design context. Both the usefulness of the existing knowledge to aid current design

  10. Aerodynamic Design of Axial-flow Compressors. Volume 2

    NASA Technical Reports Server (NTRS)

    1956-01-01

    Available experimental two-dimensional-cascade data for conventional compressor blade sections are correlated. The two-dimensional cascade and some of the principal aerodynamic factors involved in its operation are first briefly described. Then the data are analyzed by examining the variation of cascade performance at a reference incidence angle in the region of minimum loss. Variations of reference incidence angle, total-pressure loss, and deviation angle with cascade geometry, inlet Mach number, and Reynolds number are investigated. From the analysis and the correlations of the available data, rules and relations are evolved for the prediction of the magnitude of the reference total-pressure loss and the reference deviation and incidence angles for conventional blade profiles. These relations are developed in simplified forms readily applicable to compressor design procedures.

  11. Hypersonic Arbitrary-Body Aerodynamics (HABA) for conceptual design

    SciTech Connect

    Salguero, D.E.

    1990-03-15

    The Hypersonic Arbitrary-Body Aerodynamics (HABA) computer program predicts static and dynamic aerodynamic derivatives at hypersonic speeds for any vehicle geometry. It is intended to be used during conceptual design studies where fast computational speed is required. It uses the same geometry and hypersonic aerodynamic methods as the Mark IV Supersonic/Hypersonic Arbitrary-Body Program (SHABP) developed under sponsorship of the Air Force Flight Dynamics Laboratory; however, the input and output formats have been improved to make it easier to use. This program is available as part of the Department 9140 CAE software.

  12. Aerodynamic Design Study of Advanced Multistage Axial Compressor

    NASA Technical Reports Server (NTRS)

    Larosiliere, Louis M.; Wood, Jerry R.; Hathaway, Michael D.; Medd, Adam J.; Dang, Thong Q.

    2002-01-01

    As a direct response to the need for further performance gains from current multistage axial compressors, an investigation of advanced aerodynamic design concepts that will lead to compact, high-efficiency, and wide-operability configurations is being pursued. Part I of this report describes the projected level of technical advancement relative to the state of the art and quantifies it in terms of basic aerodynamic technology elements of current design systems. A rational enhancement of these elements is shown to lead to a substantial expansion of the design and operability space. Aerodynamic design considerations for a four-stage core compressor intended to serve as a vehicle to develop, integrate, and demonstrate aerotechnology advancements are discussed. This design is biased toward high efficiency at high loading. Three-dimensional blading and spanwise tailoring of vector diagrams guided by computational fluid dynamics (CFD) are used to manage the aerodynamics of the high-loaded endwall regions. Certain deleterious flow features, such as leakage-vortex-dominated endwall flow and strong shock-boundary-layer interactions, were identified and targeted for improvement. However, the preliminary results were encouraging and the front two stages were extracted for further aerodynamic trimming using a three-dimensional inverse design method described in part II of this report. The benefits of the inverse design method are illustrated by developing an appropriate pressure-loading strategy for transonic blading and applying it to reblade the rotors in the front two stages of the four-stage configuration. Multistage CFD simulations based on the average passage formulation indicated an overall efficiency potential far exceeding current practice for the front two stages. Results of the CFD simulation at the aerodynamic design point are interrogated to identify areas requiring additional development. In spite of the significantly higher aerodynamic loadings, advanced CFD

  13. The aerodynamic design of a compressor-drive turbine for use in a 75 kw automotive engine. [with tip diameter of 11.15 cm

    NASA Technical Reports Server (NTRS)

    Roelke, R. J.; Mclallin, K. L.

    1975-01-01

    The design of a single stage axial-flow turbine with a tip diameter of 11.15 cm is presented. The design specifications are given, and the aerodynamic design procedure is described. The aerodynamic information includes the results of flow path, velocity diagram, and blade profile studies. Predicted off-design performance characteristics are also presented.

  14. Development of an efficient procedure for calculating the aerodynamic effects of planform variation

    NASA Technical Reports Server (NTRS)

    Mercer, J. E.; Geller, E. W.

    1981-01-01

    Numerical procedures to compute gradients in aerodynamic loading due to planform shape changes using panel method codes were studied. Two procedures were investigated: one computed the aerodynamic perturbation directly; the other computed the aerodynamic loading on the perturbed planform and on the base planform and then differenced these values to obtain the perturbation in loading. It is indicated that computing the perturbed values directly can not be done satisfactorily without proper aerodynamic representation of the pressure singularity at the leading edge of a thin wing. For the alternative procedure, a technique was developed which saves most of the time-consuming computations from a panel method calculation for the base planform. Using this procedure the perturbed loading can be calculated in about one-tenth the time of that for the base solution.

  15. Optimum aerodynamic design via boundary control

    NASA Technical Reports Server (NTRS)

    Jameson, Antony

    1994-01-01

    These lectures describe the implementation of optimization techniques based on control theory for airfoil and wing design. In previous studies it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. Recently the method has been implemented in an alternative formulation which does not depend on conformal mapping, so that it can more easily be extended to treat general configurations. The method has also been extended to treat the Euler equations, and results are presented for both two and three dimensional cases, including the optimization of a swept wing.

  16. Improved Aerodynamic Analysis for Hybrid Wing Body Conceptual Design Optimization

    NASA Technical Reports Server (NTRS)

    Gern, Frank H.

    2012-01-01

    This paper provides an overview of ongoing efforts to develop, evaluate, and validate different tools for improved aerodynamic modeling and systems analysis of Hybrid Wing Body (HWB) aircraft configurations. Results are being presented for the evaluation of different aerodynamic tools including panel methods, enhanced panel methods with viscous drag prediction, and computational fluid dynamics. Emphasis is placed on proper prediction of aerodynamic loads for structural sizing as well as viscous drag prediction to develop drag polars for HWB conceptual design optimization. Data from transonic wind tunnel tests at the Arnold Engineering Development Center s 16-Foot Transonic Tunnel was used as a reference data set in order to evaluate the accuracy of the aerodynamic tools. Triangularized surface data and Vehicle Sketch Pad (VSP) models of an X-48B 2% scale wind tunnel model were used to generate input and model files for the different analysis tools. In support of ongoing HWB scaling studies within the NASA Environmentally Responsible Aviation (ERA) program, an improved finite element based structural analysis and weight estimation tool for HWB center bodies is currently under development. Aerodynamic results from these analyses are used to provide additional aerodynamic validation data.

  17. Extended mapping and characteristics techniques for inverse aerodynamic design

    NASA Technical Reports Server (NTRS)

    Sobieczky, H.; Qian, Y. J.

    1991-01-01

    Some ideas for using hodograph theory, mapping techniques and methods of characteristics to formulate typical aerodynamic design boundary value problems are developed. The inverse method of characteristics is shown to be a fast tool for design of transonic flow elements as well as supersonic flows with given shock waves.

  18. Computational Aerodynamic Simulations of a Spacecraft Cabin Ventilation Fan Design

    NASA Technical Reports Server (NTRS)

    Tweedt, Daniel L.

    2010-01-01

    Quieter working environments for astronauts are needed if future long-duration space exploration missions are to be safe and productive. Ventilation and payload cooling fans are known to be dominant sources of noise, with the International Space Station being a good case in point. To address this issue cost effectively, early attention to fan design, selection, and installation has been recommended, leading to an effort by NASA to examine the potential for small-fan noise reduction by improving fan aerodynamic design. As a preliminary part of that effort, the aerodynamics of a cabin ventilation fan designed by Hamilton Sundstrand has been simulated using computational fluid dynamics codes, and the computed solutions analyzed to quantify various aspects of the fan aerodynamics and performance. Four simulations were performed at the design rotational speed: two at the design flow rate and two at off-design flow rates. Following a brief discussion of the computational codes, various aerodynamic- and performance-related quantities derived from the computed flow fields are presented along with relevant flow field details. The results show that the computed fan performance is in generally good agreement with stated design goals.

  19. A PDE Sensitivity Equation Method for Optimal Aerodynamic Design

    NASA Technical Reports Server (NTRS)

    Borggaard, Jeff; Burns, John

    1996-01-01

    The use of gradient based optimization algorithms in inverse design is well established as a practical approach to aerodynamic design. A typical procedure uses a simulation scheme to evaluate the objective function (from the approximate states) and its gradient, then passes this information to an optimization algorithm. Once the simulation scheme (CFD flow solver) has been selected and used to provide approximate function evaluations, there are several possible approaches to the problem of computing gradients. One popular method is to differentiate the simulation scheme and compute design sensitivities that are then used to obtain gradients. Although this black-box approach has many advantages in shape optimization problems, one must compute mesh sensitivities in order to compute the design sensitivity. In this paper, we present an alternative approach using the PDE sensitivity equation to develop algorithms for computing gradients. This approach has the advantage that mesh sensitivities need not be computed. Moreover, when it is possible to use the CFD scheme for both the forward problem and the sensitivity equation, then there are computational advantages. An apparent disadvantage of this approach is that it does not always produce consistent derivatives. However, for a proper combination of discretization schemes, one can show asymptotic consistency under mesh refinement, which is often sufficient to guarantee convergence of the optimal design algorithm. In particular, we show that when asymptotically consistent schemes are combined with a trust-region optimization algorithm, the resulting optimal design method converges. We denote this approach as the sensitivity equation method. The sensitivity equation method is presented, convergence results are given and the approach is illustrated on two optimal design problems involving shocks.

  20. Advanced Aerodynamic Design of Passive Porosity Control Effectors

    NASA Technical Reports Server (NTRS)

    Hunter, Craig A.; Viken, Sally A.; Wood, Richard M.; Bauer, Steven X. S.

    2001-01-01

    This paper describes aerodynamic design work aimed at developing a passive porosity control effector system for a generic tailless fighter aircraft. As part of this work, a computational design tool was developed and used to layout passive porosity effector systems for longitudinal and lateral-directional control at a low-speed, high angle of attack condition. Aerodynamic analysis was conducted using the NASA Langley computational fluid dynamics code USM3D, in conjunction with a newly formulated surface boundary condition for passive porosity. Results indicate that passive porosity effectors can provide maneuver control increments that equal and exceed those of conventional aerodynamic effectors for low-speed, high-alpha flight, with control levels that are a linear function of porous area. This work demonstrates the tremendous potential of passive porosity to yield simple control effector systems that have no external moving parts and will preserve an aircraft's fixed outer mold line.

  1. Preliminary aerodynamic design considerations for advanced laminar flow aircraft configurations

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph L., Jr.; Yip, Long P.; Jordan, Frank L., Jr.

    1986-01-01

    Modern composite manufacturing methods have provided the opportunity for smooth surfaces that can sustain large regions of natural laminar flow (NLF) boundary layer behavior and have stimulated interest in developing advanced NLF airfoils and improved aircraft designs. Some of the preliminary results obtained in exploratory research investigations on advanced aircraft configurations at the NASA Langley Research Center are discussed. Results of the initial studies have shown that the aerodynamic effects of configuration variables such as canard/wing arrangements, airfoils, and pusher-type and tractor-type propeller installations can be particularly significant at high angles of attack. Flow field interactions between aircraft components were shown to produce undesirable aerodynamic effects on a wing behind a heavily loaded canard, and the use of properly designed wing leading-edge modifications, such as a leading-edge droop, offset the undesirable aerodynamic effects by delaying wing stall and providing increased stall/spin resistance with minimum degradation of laminar flow behavior.

  2. AERODYNAMIC AND BLADING DESIGN OF MULTISTAGE AXIAL FLOW COMPRESSORS

    NASA Technical Reports Server (NTRS)

    Crouse, J. E.

    1994-01-01

    The axial-flow compressor is used for aircraft engines because it has distinct configuration and performance advantages over other compressor types. However, good potential performance is not easily obtained. The designer must be able to model the actual flows well enough to adequately predict aerodynamic performance. This computer program has been developed for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis. The aerodynamic solution gives velocity diagrams on selected streamlines of revolution at the blade row edges. The program yields aerodynamic and blading design results that can be directly used by flow and mechanical analysis codes. Two such codes are TSONIC, a blade-to-blade channel flow analysis code (COSMIC program LEW-10977), and MERIDL, a more detailed hub-to-shroud flow analysis code (COSMIC program LEW-12966). The aerodynamic and blading design program can reduce the time and effort required to obtain acceptable multistage axial-flow compressor configurations by generating good initial solutions and by being compatible with available analysis codes. The aerodynamic solution assumes steady, axisymmetric flow so that the problem is reduced to solving the two-dimensional flow field in the meridional plane. The streamline curvature method is used for the iterative aerodynamic solution at stations outside of the blade rows. If a blade design is desired, the blade elements are defined and stacked within the aerodynamic solution iteration. The blade element inlet and outlet angles are established by empirical incidence and deviation angles to the relative flow angles of the velocity diagrams. The blade element centerline is composed of two segments tangentially joined at a transition point. The local blade angle variation of each element can be specified as a fourth-degree polynomial function of path distance. Blade element thickness can also be specified

  3. Innovation in Aerodynamic Design Features of Soviet Missiles

    NASA Technical Reports Server (NTRS)

    Spearman, M. Leroy

    2006-01-01

    Wind tunnel investigations of some tactical and strategic missile systems developed by the former Soviet Union have been included in the basic missile research programs of the NACA/NASA. Studies of the Soviet missiles sometimes revealed innovative design features that resulted in unusual or unexpected aerodynamic characteristics. In some cases these characteristics have been such that the measured performance of the missile exceeds what might have been predicted. In other cases some unusual design features have been found that would alleviate what might otherwise have been a serious aerodynamic problem. In some designs, what has appeared to be a lack of refinement has proven to be a matter of expediency. It is a purpose of this paper to describe some examples of unusual design features of some Soviet missiles and to illustrate the effectiveness of the design features on the aerodynamic behavior of the missile. The paper draws on the experience of the author who for over 60 years was involved in the aerodynamic wind tunnel testing of aircraft and missiles with the NACA/NASA.

  4. Computational methods for aerodynamic design using numerical optimization

    NASA Technical Reports Server (NTRS)

    Peeters, M. F.

    1983-01-01

    Five methods to increase the computational efficiency of aerodynamic design using numerical optimization, by reducing the computer time required to perform gradient calculations, are examined. The most promising method consists of drastically reducing the size of the computational domain on which aerodynamic calculations are made during gradient calculations. Since a gradient calculation requires the solution of the flow about an airfoil whose geometry was slightly perturbed from a base airfoil, the flow about the base airfoil is used to determine boundary conditions on the reduced computational domain. This method worked well in subcritical flow.

  5. Aerodynamic design optimization by using a continuous adjoint method

    NASA Astrophysics Data System (ADS)

    Luo, JiaQi; Xiong, JunTao; Liu, Feng

    2014-07-01

    This paper presents the fundamentals of a continuous adjoint method and the applications of this method to the aerodynamic design optimization of both external and internal flows. General formulation of the continuous adjoint equations and the corresponding boundary conditions are derived. With the adjoint method, the complete gradient information needed in the design optimization can be obtained by solving the governing flow equations and the corresponding adjoint equations only once for each cost function, regardless of the number of design parameters. An inverse design of airfoil is firstly performed to study the accuracy of the adjoint gradient and the effectiveness of the adjoint method as an inverse design method. Then the method is used to perform a series of single and multiple point design optimization problems involving the drag reduction of airfoil, wing, and wing-body configuration, and the aerodynamic performance improvement of turbine and compressor blade rows. The results demonstrate that the continuous adjoint method can efficiently and significantly improve the aerodynamic performance of the design in a shape optimization problem.

  6. Aerodynamic Design Study of an Advanced Active Twist Rotor

    NASA Technical Reports Server (NTRS)

    Sekula, Martin K.; Wilbur, Matthew L.; Yeager, William T., Jr.

    2003-01-01

    An Advanced Active Twist Rotor (AATR) is currently being developed by the U.S. Army Vehicle Technology Directorate at NASA Langley Research Center. As a part of this effort, an analytical study was conducted to determine the impact of blade geometry on active-twist performance and, based on those findings, propose a candidate aerodynamic design for the AATR. The process began by creating a baseline design which combined the dynamic design of the original Active Twist Rotor and the aerodynamic design of a high lift rotor concept. The baseline model was used to conduct a series of parametric studies to examine the effect of linear blade twist and blade tip sweep, droop, and taper on active-twist performance. Rotor power requirements and hub vibration were also examined at flight conditions ranging from hover to advance ratio = 0.40. A total of 108 candidate designs were analyzed using the second-generation version of the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II) code. The study concluded that the vibration reduction capabilities of a rotor utilizing controlled, strain-induced twisting are enhanced through the incorporation of blade tip sweep, droop, and taper into the blade design, while they are degraded by increasing the nose-down linear blade twist. Based on the analysis of rotor power, hub vibration, and active-twist response, a candidate aerodynamic design for the AATR consisting of a blade with approximately 10 degrees of linear blade twist and a blade tip design with 30 degree sweep, 10 degree droop, and 2.5:1 taper ratio over the outer five percent of the blade is proposed.

  7. Designing Flight Deck Procedures

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Wiener, Earl

    2005-01-01

    Three reports address the design of flight-deck procedures and various aspects of human interaction with cockpit systems that have direct impact on flight safety. One report, On the Typography of Flight- Deck Documentation, discusses basic research about typography and the kind of information needed by designers of flight deck documentation. Flight crews reading poorly designed documentation may easily overlook a crucial item on the checklist. The report surveys and summarizes the available literature regarding the design and typographical aspects of printed material. It focuses on typographical factors such as proper typefaces, character height, use of lower- and upper-case characters, line length, and spacing. Graphical aspects such as layout, color coding, fonts, and character contrast are discussed; and several cockpit conditions such as lighting levels and glare are addressed, as well as usage factors such as angular alignment, paper quality, and colors. Most of the insights and recommendations discussed in this report are transferable to paperless cockpit systems of the future and computer-based procedure displays (e.g., "electronic flight bag") in aerospace systems and similar systems that are used in other industries such as medical, nuclear systems, maritime operations, and military systems.

  8. A New Aerodynamic Data Dispersion Method for Launch Vehicle Design

    NASA Technical Reports Server (NTRS)

    Pinier, Jeremy T.

    2011-01-01

    A novel method for implementing aerodynamic data dispersion analysis is herein introduced. A general mathematical approach combined with physical modeling tailored to the aerodynamic quantity of interest enables the generation of more realistically relevant dispersed data and, in turn, more reasonable flight simulation results. The method simultaneously allows for the aerodynamic quantities and their derivatives to be dispersed given a set of non-arbitrary constraints, which stresses the controls model in more ways than with the traditional bias up or down of the nominal data within the uncertainty bounds. The adoption and implementation of this new method within the NASA Ares I Crew Launch Vehicle Project has resulted in significant increases in predicted roll control authority, and lowered the induced risks for flight test operations. One direct impact on launch vehicles is a reduced size for auxiliary control systems, and the possibility of an increased payload. This technique has the potential of being applied to problems in multiple areas where nominal data together with uncertainties are used to produce simulations using Monte Carlo type random sampling methods. It is recommended that a tailored physics-based dispersion model be delivered with any aerodynamic product that includes nominal data and uncertainties, in order to make flight simulations more realistic and allow for leaner spacecraft designs.

  9. An analytical procedure for evaluating shuttle abort staging aerodynamic characteristics

    NASA Technical Reports Server (NTRS)

    Meyer, R.

    1973-01-01

    An engineering analysis and computer code (AERSEP) for predicting Space Shuttle Orbiter - HO Tank longitudinal aerodynamic characteristics during abort separation has been developed. Computed results are applicable at Mach numbers above 2 for angle-of-attack between plus or minus 10 degrees. No practical restrictions on orbiter-tank relative positioning are indicated for tank-under-orbiter configurations. Input data requirements and computer running times are minimal facilitating program use for parametric studies, test planning, and trajectory analysis. In a majority of cases AERSEP Orbiter-Tank interference predictions are as accurate as state-of-the-art estimates for interference-free or isolated-vehicle configurations. AERSEP isolated-orbiter predictions also show excellent correlation with data.

  10. Aerodynamic characteristics of missile configurations based on Soviet design concepts

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1979-01-01

    The aerodynamic characteristics of several missile concepts are examined. The configurations, which are based on some typical Soviet design concepts, include fixed-wing missiles with either forward- or aft-tail controls, and wing-control missiles with fixed aft stabilizing surfaces. The conceptual missions include air-to-air, surface-to-air, air-to-surface, and surface-to-surface. Analytical and experimental results indicate that through the proper shaping and location of components, and through the exploitation of local flow fields, the concepts provide generally good stability characteristics, high control effectiveness, and low control hinge moments. In addition, in the case of some cruise-type missions, there are indications of the application of area ruling as a means of improving the aerodynamic efficiency. In general, a point-design philosophy is indicated whereby a particular configuration is developed for performing a particular mission.

  11. Study on aerodynamic design optimization of turbomachinery blades

    NASA Astrophysics Data System (ADS)

    Chen, Naixing; Zhang, Hongwu; Huang, Weiguang; Xu, Yanji

    2005-12-01

    This paper describes the study on aerodynamics design optimization of turbomachinery blading developed by the authors at the Institute of Engineering Thermophysics, Chinese Academy of Sciences, during the recent few years. The present paper describes the aspects mainly on how to use a rapid approach of profiling a 3D blading and of grid generation for computation, a fast and accurate viscous computation method and an appropriate optimization methodology including a blade parameterization algorithm to optimize turbomachinery blading aerodynamically. Any blade configuration can be expressed by three curves, they are the camber lines, the thickness distributions and the radial stacking line, and then the blade geometry can be easily parameterized by a number of parameters with three polynomials. A gradient-based parameterization analytical method and a response surface method were applied herein for blade optimization. It was found that the optimization process provides reliable design for turbomachinery with reasonable computing time.

  12. Missile autopilot design considering uncertainties in aerodynamics and actuator dynamics

    NASA Astrophysics Data System (ADS)

    Song, Yong D.; Hou, J.; Fogson, F.

    2000-07-01

    This work presents a method for missile autopilot design in the presence of actuator and uncertain dynamics. Nonlinear control algorithms are derived based on both missile aerodynamics and actuator dynamics. To account for system nonlinearities and uncertainties due to varying flight conditions, a memory-based compensation unit is developed and integrated into the strategy. Simulation on EMRAAT missile validates the effectiveness of the proposed control method.

  13. Comprehensive missile aerodynamics programs for preliminary design

    NASA Technical Reports Server (NTRS)

    Dillenius, M. F. E.; Hemsch, M. J.; Sawyer, W. C.; Allen, J. M.; Blair, A. B., Jr.

    1982-01-01

    Two different classes of missile aeroprediction programs have been recently developed. The first class of programs provides rapid engineering predictions and includes MISSILE1 and MISSILE2 applicable to missile configurations with axisymmetric bodies. The second class of programs consists of the DEMON series, including a simplified version NSWCDM, designed to calculate detailed loadings acting on supersonic missiles which may have non-circular body cross sections. Both classes account for high angles of attack and track vortices from canard or wing section to the tail section. Extensive comparisons with experimental data are presented including nonlinear effects of canard control.

  14. Reduced truck fuel consumption through aerodynamic design

    NASA Technical Reports Server (NTRS)

    Steers, L. L.; Saltzman, E. J.

    1977-01-01

    Full-scale fuel consumption and drag tests were performed on a conventional cab-over-engine tractor-trailer combination and a version of the same vehicle with significant forebody modifications. The modified configuration had greatly increased radii on all front corners and edges of the tractor and a smooth fairing of the modified tractor top and sides extending to the trailer. Concurrent highway testing of the two configurations showed that the modified design used 20% to 24% less fuel than the baseline configuration at 88.5 km/hr (55 mph) with near-calm wind conditions. Coastdown test results showed that the modified configuration reduced the drag coefficient by 0.43 from the baseline value of 1.17 at 88.5 km/hr (55 mph) in calm wind conditions.

  15. Aerodynamic Design on Unstructured Grids for Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Anderson, W. Kyle; Bonhaus, Daryl L.

    1997-01-01

    An aerodynamic design algorithm for turbulent flows using unstructured grids is described. The current approach uses adjoint (costate) variables for obtaining derivatives of the cost function. The solution of the adjoint equations is obtained using an implicit formulation in which the turbulence model is fully coupled with the flow equations when solving for the costate variables. The accuracy of the derivatives is demonstrated by comparison with finite-difference gradients and a few example computations are shown. In addition, a user interface is described which significantly reduces the time required for setting up the design problems. Recommendations on directions of further research into the Navier Stokes design process are made.

  16. Small, high pressure ratio compressor: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Bryce, C. A.; Erwin, J. R.; Perrone, G. L.; Nelson, E. L.; Tu, R. K.; Bosco, A.

    1973-01-01

    The Small, High-Pressure-Ratio Compressor Program was directed toward the analysis, design, and fabrication of a centrifugal compressor providing a 6:1 pressure ratio and an airflow rate of 2.0 pounds per second. The program consists of preliminary design, detailed areodynamic design, mechanical design, and mechanical acceptance tests. The preliminary design evaluate radial- and backward-curved blades, tandem bladed impellers, impeller-and diffuser-passage boundary-layer control, and vane, pipe, and multiple-stage diffusers. Based on this evaluation, a configuration was selected for detailed aerodynamic and mechanical design. Mechanical acceptance test was performed to demonstrate that mechanical design objectives of the research package were met.

  17. Development and application of an optimization procedure for flutter suppression using the aerodynamic energy concept

    NASA Technical Reports Server (NTRS)

    Nissim, E.; Abel, I.

    1978-01-01

    An optimization procedure is developed based on the responses of a system to continuous gust inputs. The procedure uses control law transfer functions which have been partially determined by using the relaxed aerodynamic energy approach. The optimization procedure yields a flutter suppression system which minimizes control surface activity in a gust environment. The procedure is applied to wing flutter of a drone aircraft to demonstrate a 44 percent increase in the basic wing flutter dynamic pressure. It is shown that a trailing edge control system suppresses the flutter instability over a wide range of subsonic mach numbers and flight altitudes. Results of this study confirm the effectiveness of the relaxed energy approach.

  18. Nonlinear potential analysis techniques for supersonic-hypersonic aerodynamic design

    NASA Technical Reports Server (NTRS)

    Shankar, V.; Clever, W. C.

    1984-01-01

    Approximate nonlinear inviscid theoretical techniques for predicting aerodynamic characteristics and surface pressures for relatively slender vehicles at supersonic and moderate hypersonic speeds were developed. Emphasis was placed on approaches that would be responsive to conceptual configuration design level of effort. Second order small disturbance and full potential theory was utilized to meet this objective. Numerical codes were developed for relatively general three dimensional geometries to evaluate the capability of the approximate equations of motion considered. Results from the computations indicate good agreement with experimental results for a variety of wing, body, and wing-body shapes.

  19. Design Exploration of Aerodynamic Wing Shape for RLV Flyback Booster

    NASA Astrophysics Data System (ADS)

    Chiba, Kazuhisa; Obayashi, Shigeru; Nakahashi, Kazuhiro

    The wing shape of flyback booster for a Two-Stage-To-Orbit reusable launch vehicle has been optimized considering four objectives. The objectives are to minimize the shift of aerodynamic center between supersonic and transonic conditions, transonic pitching moment and transonic drag coefficient, as well as to maximize subsonic lift coefficient. The three-dimensional Reynolds-averaged Navier-Stokes computation using the modified Spalart-Allmaras one-equation model is used in aerodynamic evaluation accounting for possible flow separations. Adaptive range multi-objective genetic algorithm is used for the present study because tradeoff can be obtained using a smaller number of individuals than conventional multi-objective genetic algorithms. Consequently, four-objective optimization has produced 102 non-dominated solutions, which represent tradeoff information among four objective functions. Moreover, Self-Organizing Maps have been used to analyze the present non-dominated solutions and to visualize tradeoffs and influence of design variables to the four objectives. Self-Organizing Maps contoured by the four objective functions and design variables are found to visualize tradeoffs and effects of each design variable.

  20. Wind turbine trailing-edge aerodynamic brake design

    SciTech Connect

    Quandt, G.

    1996-01-01

    This report describes the design of a centrifugally actuated aerodynamic-overspeed device for a horizontal-axis wind turbine. The device will meet the following criteria; (1) It will be effective for airfoil angles of attack 0{degrees} to 45{degrees}. (2) It will be stowed inside the blade profile prior to deployment. (3) It will be capable of offsetting the positive torque produced by the overall blade. (4) Hinge moments will be minimized to lower actuator loads and cost. (5) It will be evaluated as a potential power modulating active rotor-control system. A literature review of aerodynamic braking devices was conducted. Information from the literature review was used to conceptualize the most effective devices for subsequent testing and design. Wind-tunnel test data for several braking devices are presented in this report. Using the data for the most promising configuration, a preliminary design was developed for a MICON 65/13 wind turbine with Phoenix 7.9-m rotor blades.

  1. Aerodynamics and design for ultra-low Reynolds number flight

    NASA Astrophysics Data System (ADS)

    Kunz, Peter Josef

    Growing interest in micro-air-vehicles has created the need for improved understanding of the relevant aerodynamics. A reasonable starting point is the study of airfoil aerodynamics at Reynolds numbers below 10,000, here termed ultra-low Reynolds numbers. The effects of airfoil geometry on performance are explored using an incompressible Navier-Stokes solver. Variations in thickness, camber, and the shape of leading and trailing edges are studied. Results indicate an increase in maximum lift coefficient with decreasing Reynolds number, but the lift to drag ratio continues to decrease, making the power required for flight a more restrictive consideration than lift. This performance penalty can be mitigated by careful airfoil design. Contrary to the notion that viscous fairing reduces airfoil geometry effectiveness, the computational results indicate that geometry still has a profound effect on performance at ultra-low Reynolds numbers. To further explore this design space, the flow solver has been coupled with an optimizer, resulting in the first airfoils quantitatively designed for this flow regime and demonstrating that unconventional camberlines can offer significant performance gains. Building on these results, tools are developed for ultra-low Reynolds number rotors combining enhanced classical rotor theory with airfoil data from Navier-Stokes calculations. This performance prediction method is coupled with optimization for both design and analysis. Performance predictions from these tools are compared with three-dimensional Navier-Stokes analyses and experimental data for several micro-rotor designs. Comparisons among the analyses and experimental data show reasonable agreement both in the global thrust and power, but the spanwise distributions of these quantities exhibit deviations, partially attributable to three-dimensional and rotational effects that effectively modify airfoil section performance. While these issues may limit the applicability of blade

  2. Aerodynamic Design of Wing based on Humpback Whale Flipper

    NASA Astrophysics Data System (ADS)

    Akram, Saif; Baig, Faisal

    2013-11-01

    The tubercles provide a bio-inspired design that has commercial viability for wing-like structures. Wind tunnel tests at low speeds of model humpback flippers with leading-edge tubercles have demonstrated improvements tubercles make, such as a staggering 32% reduction in drag, 8% improvement in lift, and a 40% increase in angle of attack over smooth flippers before stalling. The tubercles on the leading edge act as a passive-flow control device that improves the performance and maneuverability of the flipper. Possible fluid-dynamic mechanisms for improved performance include delay of stall through generation of a vortex and modification of the boundary layer, and increase in effective span by reduction of both spanwise flow and strength of the tip vortex. In the present work, numerical investigation of a 3D wing with scalloped leading edge inspired by the humpback whale flipper is carried out at high subsonic speeds with variation in angle of attack from 0 to 25 degrees. The effect of using different turbulence models is also investigated in order to attain a better understanding of mechanism(s) responsible for improved aerodynamic performance. This new understanding of humpback whale flipper aerodynamics has strong implications for wing design.

  3. Team Software Development for Aerothermodynamic and Aerodynamic Analysis and Design

    NASA Technical Reports Server (NTRS)

    Alexandrov, N.; Atkins, H. L.; Bibb, K. L.; Biedron, R. T.; Carpenter, M. H.; Gnoffo, P. A.; Hammond, D. P.; Jones, W. T.; Kleb, W. L.; Lee-Rausch, E. M.

    2003-01-01

    A collaborative approach to software development is described. The approach employs the agile development techniques: project retrospectives, Scrum status meetings, and elements of Extreme Programming to efficiently develop a cohesive and extensible software suite. The software product under development is a fluid dynamics simulator for performing aerodynamic and aerothermodynamic analysis and design. The functionality of the software product is achieved both through the merging, with substantial rewrite, of separate legacy codes and the authorship of new routines. Examples of rapid implementation of new functionality demonstrate the benefits obtained with this agile software development process. The appendix contains a discussion of coding issues encountered while porting legacy Fortran 77 code to Fortran 95, software design principles, and a Fortran 95 coding standard.

  4. Design, aerodynamics and autonomy of the DelFly.

    PubMed

    de Croon, G C H E; Groen, M A; De Wagter, C; Remes, B; Ruijsink, R; van Oudheusden, B W

    2012-06-01

    One of the major challenges in robotics is to develop a fly-like robot that can autonomously fly around in unknown environments. In this paper, we discuss the current state of the DelFly project, in which we follow a top-down approach to ever smaller and more autonomous ornithopters. The presented findings concerning the design, aerodynamics and autonomy of the DelFly illustrate some of the properties of the top-down approach, which allows the identification and resolution of issues that also play a role at smaller scales. A parametric variation of the wing stiffener layout produced a 5% more power-efficient wing. An experimental aerodynamic investigation revealed that this could be associated with an improved stiffness of the wing, while further providing evidence of the vortex development during the flap cycle. The presented experiments resulted in an improvement in the generated lift, allowing the inclusion of a yaw rate gyro, pressure sensor and microcontroller onboard the DelFly. The autonomy of the DelFly is expanded by achieving (1) an improved turning logic to obtain better vision-based obstacle avoidance performance in environments with varying texture and (2) successful onboard height control based on the pressure sensor. PMID:22617112

  5. Investigation of aerodynamic design issues with regions of separated flow

    NASA Technical Reports Server (NTRS)

    Gally, Tom

    1993-01-01

    Existing aerodynamic design methods have generally concentrated on the optimization of airfoil or wing shapes to produce a minimum drag while satisfying some basic constraints such as lift, pitching moment, or thickness. Since the minimization of drag almost always precludes the existence of separated flow, the evaluation and validation of these design methods for their robustness and accuracy when separated flow is present has not been aggressively pursued. However, two new applications for these design tools may be expected to include separated flow and the issues of aerodynamic design with this feature must be addressed. The first application of the aerodynamic design tools is the design of airfoils or wings to provide an optimal performance over a wide range of flight conditions (multipoint design). While the definition of 'optimal performance' in the multipoint setting is currently being hashed out, it is recognized that given a wide range of flight conditions, it will not be possible to ensure a minimum drag constraint at all conditions, and in fact some amount of separated flow (presumably small) may have to be allowed at the more demanding flight conditions. Thus a multipoint design method must be tolerant of the existence of separated flow and may include some controls upon its extent. The second application is in the design of wings with extended high speed buffet boundaries of their flight envelopes. Buffet occurs on a wing when regions of flow separation have grown to the extent that their time varying pressures induce possible destructive effects upon the wing structure or adversely effect either the aircraft controllability or passenger comfort. A conservative approach to the expansion of the buffet flight boundary is to simply expand the flight envelope of nonseparated flow under the assumption that buffet will also thus be alleviated. However, having the ability to design a wing with separated flow and thus to control the location, extent and

  6. Aerodynamic and acoustic investigation of inverted velocity profile coannular exhaust nozzle models and development of aerodynamic and acoustic prediction procedures

    NASA Technical Reports Server (NTRS)

    Larson, R. S.; Nelson, D. P.; Stevens, B. S.

    1979-01-01

    Five co-annular nozzle models, covering a systematic variation of nozzle geometry, were tested statically over a range of exhaust conditions including inverted velocity profile (IVP) (fan to primary stream velocity ratio 1) and non IVP profiles. Fan nozzle pressure ratio (FNPR) was varied from 1.3 to 4.1 at primary nozzle pressure ratios (PNPR) of 1.53 and 2.0. Fan stream temperatures of 700 K (1260 deg R) and 1089 K(1960 deg R) were tested with primary stream temperatures of 700 K (1260 deg R), 811 K (1460 deg R), and 1089 K (1960 deg R). At fan and primary stream velocities of 610 and 427 m/sec (2000 and 1400 ft/sec), respectively, increasing fan radius ratio from 0.69 to 0.83 reduced peak perceived noise level (PNL) 3 dB, and an increase in primary radius ratio from 0 to 0.81 (fan radius ratio constant at 0.83) reduced peak PNL an additional 1.0 dB. There were no noise reductions at a fan stream velocity of 853 m/sec (2800 ft/sec). Increasing fan radius ratio from 0.69 to 0.83 reduced nozzle thrust coefficient 1.2 to 1.5% at a PNPR of 1.53, and 1.7 to 2.0% at a PNPR of 2.0. The developed acoustic prediction procedure collapsed the existing data with standard deviation varying from + or - 8 dB to + or - 7 dB. The aerodynamic performance prediction procedure collapsed thrust coefficient measurements to within + or - .004 at a FNPR of 4.0 and a PNPR of 2.0.

  7. Aerodynamic Characteristics of Two Rotary Wing UAV Designs

    NASA Technical Reports Server (NTRS)

    Jones, Henry E.; Wong, Oliver D.; Noonan, Kevin W.; Reis, Deane G.; Malovrh, Brendon D.

    2006-01-01

    This paper presents the results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of a parametric study of fixed system lift and drag coefficient response to changes in configuration and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect both the character and magnitude of the response. The affect of scaled stores on body drag is observed to be dependent on body shape.

  8. AERODYNAMIC CHARACTERISTICS OF TWO ROTARY WING UAV DESIGNS

    NASA Technical Reports Server (NTRS)

    Jones, Henry E.; Wong, Oliver D.; Noonan, Kevin W.; Reis, Deane G.; Malovrh, Brendon D.

    2006-01-01

    This paper presents the results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of a parametric study of fixed system lift and drag coefficient response to changes in configuration and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect both the character and magnitude of the response. The affect of scaled stores on body drag is observed to be dependent on body shape.

  9. Optimum Design of Insulated Compression Plates Subjected to Aerodynamic Heating

    NASA Technical Reports Server (NTRS)

    Davidson, John R.; Dalby, James F.

    1961-01-01

    A method to determine the optimum thicknesses of insulation and load-carrying structure has been applied to insulated compression plates subjected to aerodynamic heating. The optimum design results in the lowest combined weight of insulation and load-carrying plate. Load parameters which included the imposed load, insulation conductivity and density, and flight time were found for design strength criteria of compressive yield, compressive buckling, and postbuckling failure. Charts of optimum total weight were prepared for 2024-T3 aluminum alloy, HK3lA magnesium alloy, 17-7 PH stainless steel, and Inconel X for each design criterion. The results show that 17-7 PH stainless steel and Inconel X are most efficient for compressive yield stress and that HK3lA magnesium is most efficient for buckling. HK31A magnesium is also most efficient for the postbuckling failure criterion except under conditions of light loading and long flight periods; under such conditions uninsulated Inconel X may be superior for environmental temperature less than 1,200 F. Insulated magnesium is more efficient than insulated aluminum because the lower density of magnesium permits the use of thick plates with large heat capacity. When more than one failure mode was applied to a design, it was found that the minimum weight structure was one in which all modes of failure occurred at the design load.

  10. Parametric Deformation of Discrete Geometry for Aerodynamic Shape Design

    NASA Technical Reports Server (NTRS)

    Anderson, George R.; Aftosmis, Michael J.; Nemec, Marian

    2012-01-01

    We present a versatile discrete geometry manipulation platform for aerospace vehicle shape optimization. The platform is based on the geometry kernel of an open-source modeling tool called Blender and offers access to four parametric deformation techniques: lattice, cage-based, skeletal, and direct manipulation. Custom deformation methods are implemented as plugins, and the kernel is controlled through a scripting interface. Surface sensitivities are provided to support gradient-based optimization. The platform architecture allows the use of geometry pipelines, where multiple modelers are used in sequence, enabling manipulation difficult or impossible to achieve with a constructive modeler or deformer alone. We implement an intuitive custom deformation method in which a set of surface points serve as the design variables and user-specified constraints are intrinsically satisfied. We test our geometry platform on several design examples using an aerodynamic design framework based on Cartesian grids. We examine inverse airfoil design and shape matching and perform lift-constrained drag minimization on an airfoil with thickness constraints. A transport wing-fuselage integration problem demonstrates the approach in 3D. In a final example, our platform is pipelined with a constructive modeler to parabolically sweep a wingtip while applying a 1-G loading deformation across the wingspan. This work is an important first step towards the larger goal of leveraging the investment of the graphics industry to improve the state-of-the-art in aerospace geometry tools.

  11. Aerodynamic Shape Sensitivity Analysis and Design Optimization of Complex Configurations Using Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Taylor, Arthur C., III; Newman, James C., III; Barnwell, Richard W.

    1997-01-01

    A three-dimensional unstructured grid approach to aerodynamic shape sensitivity analysis and design optimization has been developed and is extended to model geometrically complex configurations. The advantage of unstructured grids (when compared with a structured-grid approach) is their inherent ability to discretize irregularly shaped domains with greater efficiency and less effort. Hence, this approach is ideally suited for geometrically complex configurations of practical interest. In this work the nonlinear Euler equations are solved using an upwind, cell-centered, finite-volume scheme. The discrete, linearized systems which result from this scheme are solved iteratively by a preconditioned conjugate-gradient-like algorithm known as GMRES for the two-dimensional geometry and a Gauss-Seidel algorithm for the three-dimensional; similar procedures are used to solve the accompanying linear aerodynamic sensitivity equations in incremental iterative form. As shown, this particular form of the sensitivity equation makes large-scale gradient-based aerodynamic optimization possible by taking advantage of memory efficient methods to construct exact Jacobian matrix-vector products. Simple parameterization techniques are utilized for demonstrative purposes. Once the surface has been deformed, the unstructured grid is adapted by considering the mesh as a system of interconnected springs. Grid sensitivities are obtained by differentiating the surface parameterization and the grid adaptation algorithms with ADIFOR (which is an advanced automatic-differentiation software tool). To demonstrate the ability of this procedure to analyze and design complex configurations of practical interest, the sensitivity analysis and shape optimization has been performed for a two-dimensional high-lift multielement airfoil and for a three-dimensional Boeing 747-200 aircraft.

  12. Optimized aerodynamic design process for subsonic transport wing fitted with winglets. [wind tunnel model

    NASA Technical Reports Server (NTRS)

    Kuhlman, J. M.

    1979-01-01

    The aerodynamic design of a wind-tunnel model of a wing representative of that of a subsonic jet transport aircraft, fitted with winglets, was performed using two recently developed optimal wing-design computer programs. Both potential flow codes use a vortex lattice representation of the near-field of the aerodynamic surfaces for determination of the required mean camber surfaces for minimum induced drag, and both codes use far-field induced drag minimization procedures to obtain the required spanloads. One code uses a discrete vortex wake model for this far-field drag computation, while the second uses a 2-D advanced panel wake model. Wing camber shapes for the two codes are very similar, but the resulting winglet camber shapes differ widely. Design techniques and considerations for these two wind-tunnel models are detailed, including a description of the necessary modifications of the design geometry to format it for use by a numerically controlled machine for the actual model construction.

  13. The aerodynamic design of the oblique flying wing supersonic transport

    NASA Technical Reports Server (NTRS)

    Vandervelden, Alexander J. M.; Kroo, Ilan

    1990-01-01

    The aerodynamic design of a supersonic oblique flying wing is strongly influenced by the requirement that passengers must be accommodated inside the wing. It was revealed that thick oblique wings of very high sweep angle can be efficient at supersonic speeds when transonic normal Mach numbers are allowed on the upper surface of the wing. The goals were motivated by the ability to design a maximum thickness, minimum size oblique flying wing. A 2-D Navier-Stokes solver was used to design airfoils up to 16 percent thickness with specified lift, drag and pitching moment. A new method was developed to calculate the required pressure distribution on the wing based on the airfoil loading, normal Mach number distribution and theoretical knowledge of the minimum drag of oblique configurations at supersonic speeds. The wing mean surface for this pressure distribution was calculated using an inverse potential flow solver. The lift to drag ratio of this wing was significantly higher than that of a comparable delta wing for cruise speeds up to Mach 2.

  14. The space shuttle ascent vehicle aerodynamic challenges configuration design and data base development

    NASA Technical Reports Server (NTRS)

    Dill, C. C.; Young, J. C.; Roberts, B. B.; Craig, M. K.; Hamilton, J. T.; Boyle, W. W.

    1985-01-01

    The phase B Space Shuttle systems definition studies resulted in a generic configuration consisting of a delta wing orbiter, and two solid rocket boosters (SRB) attached to an external fuel tank (ET). The initial challenge facing the aerodynamic community was aerodynamically optimizing, within limits, this configuration. As the Shuttle program developed and the sensitivities of the vehicle to aerodynamics were better understood the requirements of the aerodynamic data base grew. Adequately characterizing the vehicle to support the various design studies exploded the size of the data base to proportions that created a data modeling/management challenge for the aerodynamicist. The ascent aerodynamic data base originated primarily from wind tunnel test results. The complexity of the configuration rendered conventional analytic methods of little use. Initial wind tunnel tests provided results which included undesirable effects from model support tructure, inadequate element proximity, and inadequate plume simulation. The challenge to improve the quality of test results by determining the extent of these undesirable effects and subsequently develop testing techniques to eliminate them was imposed on the aerodynamic community. The challenges to the ascent aerodynamics community documented are unique due to the aerodynamic complexity of the Shuttle launch. Never before was such a complex vehicle aerodynamically characterized. The challenges were met with innovative engineering analyses/methodology development and wind tunnel testing techniques.

  15. Wind Turbine Blade Design System - Aerodynamic and Structural Analysis

    NASA Astrophysics Data System (ADS)

    Dey, Soumitr

    2011-12-01

    The ever increasing need for energy and the depletion of non-renewable energy resources has led to more advancement in the "Green Energy" field, including wind energy. An improvement in performance of a Wind Turbine will enhance its economic viability, which can be achieved by better aerodynamic designs. In the present study, a design system that has been under development for gas turbine turbomachinery has been modified for designing wind turbine blades. This is a very different approach for wind turbine blade design, but will allow it to benefit from the features inherent in the geometry flexibility and broad design space of the presented system. It starts with key overall design parameters and a low-fidelity model that is used to create the initial geometry parameters. The low-fidelity system includes the axisymmetric solver with loss models, T-Axi (Turbomachinery-AXIsymmetric), MISES blade-to-blade solver and 2D wing analysis code XFLR5. The geometry parameters are used to define sections along the span of the blade and connected to the CAD model of the wind turbine blade through CAPRI (Computational Analysis PRogramming Interface), a CAD neutral API that facilitates the use of parametric geometry definition with CAD. Either the sections or the CAD geometry is then available for CFD and Finite Element Analysis. The GE 1.5sle MW wind turbine and NERL NASA Phase VI wind turbine have been used as test cases. Details of the design system application are described, and the resulting wind turbine geometry and conditions are compared to the published results of the GE and NREL wind turbines. A 2D wing analysis code XFLR5, is used for to compare results from 2D analysis to blade-to-blade analysis and the 3D CFD analysis. This kind of comparison concludes that, from hub to 25% of the span blade to blade effects or the cascade effect has to be considered, from 25% to 75%, the blade acts as a 2d wing and from 75% to the tip 3D and tip effects have to be taken into account

  16. Computation of three-dimensional, rotational flow through turbomachinery blade rows for improved aerodynamic design studies

    NASA Technical Reports Server (NTRS)

    Subramanian, S. V.; Bozzola, R.; Povinelli, L. A.

    1986-01-01

    The performance of a three dimensional computer code developed for predicting the flowfield in stationary and rotating turbomachinery blade rows is described in this study. The four stage Runge-Kutta numerical integration scheme is used for solving the governing flow equations and yields solution to the full, three dimensional, unsteady Euler equations in cylindrical coordinates. This method is fully explicit and uses the finite volume, time marching procedure. In order to demonstrate the accuracy and efficiency of the code, steady solutions were obtained for several cascade geometries under widely varying flow conditions. Computed flowfield results are presented for a fully subsonic turbine stator and a low aspect ratio, transonic compressor rotor blade under maximum flow and peak efficiency design conditions. Comparisons with Laser Anemometer measurements and other numerical predictions are also provided to illustrate that the present method predicts important flow features with good accuracy and can be used for cost effective aerodynamic design studies.

  17. On aerodynamic design of the Savonius windmill rotor

    NASA Astrophysics Data System (ADS)

    Mojola, O. O.

    This paper examines under field conditions the performance characteristics of the Savonius windmill rotor. Test data were collected on the speed, torque and power of the rotor at a large number of wind speeds for each of seven values of the rotor overlap ratio. Field testing procedures are critically appraised and a unified approach is suggested. The performance data of the Savonius rotor are also fully discussed and design criteria established.

  18. The critical role of aerodynamic heating effects in the design of hypersonic vehicles

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.

    1989-01-01

    Hypersonic vehicles operate in a hostile aerothermal environment, which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response, creating a multidisciplinary interaction. The critical role of aerodynamic heating effects in the design of hypersonic vehicles is identified with an example of high localized heating on an engine-cowl leading edge. Recent advances is integrated fluid-thermal-structural finite-element analyses are presented.

  19. Development of mathematical models and numerical methods for aerodynamic design on multiprocessor computers

    NASA Astrophysics Data System (ADS)

    Maksimov, F. A.; Churakov, D. A.; Shevelev, Yu. D.

    2011-02-01

    Complex-geometry design and grid generation are addressed. The gasdynamic equations are solved, and the numerical results are compared with experimental data. For aerodynamic problems, a suite of mathematical and information technology tools is proposed for the support and management of geometric models of actual objects. Based on the mathematical modeling methods developed, numerical experiments can be performed for a wide class of geometric forms and the aerodynamic properties of aircraft can be predicted with allowance for the viscosity effects.

  20. Design procedures for compressor blades

    NASA Technical Reports Server (NTRS)

    Starken, H.

    1983-01-01

    The conventional methods for the design of the blades in the case of axial turbomachines are considered, taking into account difficulties concerning the determination of optimal blade profiles. These difficulties have been partly overcome as a consequence of the introduction of new numerical methods during the last few years. It is pointed out that, in the case of the subsonic range, a new procedure is now available for the determination of the form of blade profile on the basis of a given velocity distribution on the profile surface. The search for a profile form with favorable characteristics is consequently transformed into a search for a favorable velocity or pressure distribution on the blade. The distribution of velocities depends to a large degree on the characteristics of the profile boundary layers. The considered concept is not new. However, its practical implementation has only recently become possible. The employment of the new design procedure is illustrated with the aid of an example involving a concrete design problem.

  1. Aerodynamic Design and Computational Analysis of a Spacecraft Cabin Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Tweedt, Daniel L.

    2010-01-01

    Quieter working environments for astronauts are needed if future long-duration space exploration missions are to be safe and productive. Ventilation and payload cooling fans are known to be dominant sources of noise, with the International Space Station being a good case in point. To address this issue in a cost-effective way, early attention to fan design, selection, and installation has been recommended. Toward that end, NASA has begun to investigate the potential for small-fan noise reduction through improvements in fan aerodynamic design. Using tools and methodologies similar to those employed by the aircraft engine industry, most notably computational fluid dynamics (CFD) codes, the aerodynamic design of a new cabin ventilation fan has been developed, and its aerodynamic performance has been predicted and analyzed. The design, intended to serve as a baseline for future work, is discussed along with selected CFD results

  2. User's manual for an aerodynamic optimization scheeme that updates flow variables and design parameters simultaneously

    NASA Technical Reports Server (NTRS)

    Rizk, Magdi H.

    1988-01-01

    This user's manual is presented for an aerodynamic optimization program that updates flow variables and design parameters simultaneously. The program was developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The program was tested by applying it to the problem of optimizing propeller designs. Some reference to this particular application is therefore made in the manual. However, the optimization scheme is suitable for application to general aerodynamic design problems. A description of the approach used in the optimization scheme is first presented, followed by a description of the use of the program.

  3. The aerodynamic challenges of the design and development of the space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Young, J. C.; Underwood, J. M.; Hillje, E. R.; Whitnah, A. M.; Romere, P. O.; Gamble, J. D.; Roberts, B. B.; Ware, G. M.; Scallion, W. I.; Spencer, B., Jr.

    1985-01-01

    The major aerodynamic design challenge at the beginning of the United States Space Transportation System (STS) research and development phase was to design a vehicle that would fly as a spacecraft during early entry and as an aircraft during the final phase of entry. The design was further complicated because the envisioned vehicle was statically unstable during a portion of the aircraft mode of operation. The second challenge was the development of preflight aerodynamic predictions with an accuracy consistent with conducting a manned flight on the initial orbital flight. A brief history of the early contractual studies is presented highlighting the technical results and management decisions influencing the aerodynamic challenges. The configuration evolution and the development of preflight aerodynamic predictions will be reviewed. The results from the first four test flights shows excellent agreement with the preflight aerodynamic predictions over the majority of the flight regimes. The only regimes showing significant disagreement is confined primarily to early entry, where prediction of the basic vehicle trim and the influence of the reaction control system jets on the flow field were found to be deficient. Postflight results are analyzed to explain these prediction deficiencies.

  4. Integral-equation methods in steady and unsteady subsonic, transonic and supersonic aerodynamics for interdisciplinary design

    NASA Technical Reports Server (NTRS)

    Yates, E. Carson, Jr.

    1990-01-01

    Progress in the development of computational methods for steady and unsteady aerodynamics has perennially paced advancements in aeroelastic analysis and design capabilities. Since these capabilities are of growing importance in the analysis and design of high-performance aircraft, considerable effort has been directed toward the development of appropriate aerodynamic methodology. The contributions to those efforts from the integral-equations research program at the NASA Langley Research Center is reviewed. Specifically, the current scope, progress, and plans for research and development for inviscid and viscous flows are discussed, and example applications are shown in order to highlight the generality, versatility, and attractive features of this methodology.

  5. A system for aerodynamic design and analysis of supersonic aircraft. Part 4: Test cases

    NASA Technical Reports Server (NTRS)

    Middleton, W. D.; Lundry, J. L.

    1980-01-01

    An integrated system of computer programs was developed for the design and analysis of supersonic configurations. The system uses linearized theory methods for the calculation of surface pressures and supersonic area rule concepts in combination with linearized theory for calculation of aerodynamic force coefficients. Interactive graphics are optional at the user's request. Representative test cases and associated program output are presented.

  6. Computer program for aerodynamic and blading design of multistage axial-flow compressors

    NASA Technical Reports Server (NTRS)

    Crouse, J. E.; Gorrell, W. T.

    1981-01-01

    A code for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis codes is presented. Compressible flow, which is assumed to be steady and axisymmetric, is the basis for a two-dimensional solution in the meridional plane with viscous effects modeled by pressure loss coefficients and boundary layer blockage. The radial equation of motion and the continuity equation are solved with the streamline curvature method on calculation stations outside the blade rows. The annulus profile, mass flow, pressure ratio, and rotative speed are input. A number of other input parameters specify and control the blade row aerodynamics and geometry. In particular, blade element centerlines and thicknesses can be specified with fourth degree polynomials for two segments. The output includes a detailed aerodynamic solution and, if desired, blading coordinates that can be used for internal flow analysis codes.

  7. Post-Stall Aerodynamic Modeling and Gain-Scheduled Control Design

    NASA Technical Reports Server (NTRS)

    Wu, Fen; Gopalarathnam, Ashok; Kim, Sungwan

    2005-01-01

    A multidisciplinary research e.ort that combines aerodynamic modeling and gain-scheduled control design for aircraft flight at post-stall conditions is described. The aerodynamic modeling uses a decambering approach for rapid prediction of post-stall aerodynamic characteristics of multiple-wing con.gurations using known section data. The approach is successful in bringing to light multiple solutions at post-stall angles of attack right during the iteration process. The predictions agree fairly well with experimental results from wind tunnel tests. The control research was focused on actuator saturation and .ight transition between low and high angles of attack regions for near- and post-stall aircraft using advanced LPV control techniques. The new control approaches maintain adequate control capability to handle high angle of attack aircraft control with stability and performance guarantee.

  8. Supersonic airplane design optimization method for aerodynamic performance and low sonic boom

    NASA Technical Reports Server (NTRS)

    Cheung, Samson H.; Edwards, Thomas A.

    1992-01-01

    This paper presents a new methodology for the optimization of supersonic airplane designs to meet the dual design objectives of low sonic boom and high aerodynamic performance. Two sets of design parameters are used on an existing High Speed Civil Transport (HSCT) configuration to maximize the aerodynamic performance and minimize the sonic boom under the flight track. One set of the parameters perturbs the camber line of the wing sections to maximize the lift-over-drag ratio (L/D). A preliminary optimization run yielded a 3.75 percent improvement in L/D over a baseline low-boom configuration. The other set of parameters modifies the fuselage area to achieve a target F-function. Starting from an initial configuration with strong bow, wing, and tail shocks, a modified design with a flat-top signature is obtained. The methods presented can easily incorporate other design variables and objective functions. Extensions to the present capability in progress are described.

  9. An Efficient Inverse Aerodynamic Design Method For Subsonic Flows

    NASA Technical Reports Server (NTRS)

    Milholen, William E., II

    2000-01-01

    Computational Fluid Dynamics based design methods are maturing to the point that they are beginning to be used in the aircraft design process. Many design methods however have demonstrated deficiencies in the leading edge region of airfoil sections. The objective of the present research is to develop an efficient inverse design method which is valid in the leading edge region. The new design method is a streamline curvature method, and a new technique is presented for modeling the variation of the streamline curvature normal to the surface. The new design method allows the surface coordinates to move normal to the surface, and has been incorporated into the Constrained Direct Iterative Surface Curvature (CDISC) design method. The accuracy and efficiency of the design method is demonstrated using both two-dimensional and three-dimensional design cases.

  10. Aerodynamic simulation

    SciTech Connect

    Not Available

    1993-01-01

    In this article two integral computational fluid dynamics methods for steady-state and transient vehicle aerodynamic simulations are described using a Chevrolet Corvette ZR-1 surface panel model. In the last decade, road-vehicle aerodynamics have become an important design consideration. Originally, the design of low-drag shapes was given high priority due to worldwide fuel shortages that occurred in the mid-seventies. More recently, there has been increased interest in the role aerodynamics play in vehicle stability and passenger safety. Consequently, transient aerodynamics and the aerodynamics of vehicle in yaw have become important issues at the design stage. While there has been tremendous progress in Navier-Stokes methodology in the last few years, the physics of bluff-body aerodynamics are still very difficult to model correctly. Moreover, the computational effort to perform Navier-Stokes simulations from the geometric stage to complete flow solutions requires much computer time and impacts the design cycle time. In the short run, therefore, simpler methods must be used for such complicated problems. Here, two methods are described for the simulation of steady-state and transient vehicle aerodynamics.

  11. Using High Resolution Design Spaces for Aerodynamic Shape Optimization Under Uncertainty

    NASA Technical Reports Server (NTRS)

    Li, Wu; Padula, Sharon

    2004-01-01

    This paper explains why high resolution design spaces encourage traditional airfoil optimization algorithms to generate noisy shape modifications, which lead to inaccurate linear predictions of aerodynamic coefficients and potential failure of descent methods. By using auxiliary drag constraints for a simultaneous drag reduction at all design points and the least shape distortion to achieve the targeted drag reduction, an improved algorithm generates relatively smooth optimal airfoils with no severe off-design performance degradation over a range of flight conditions, in high resolution design spaces parameterized by cubic B-spline functions. Simulation results using FUN2D in Euler flows are included to show the capability of the robust aerodynamic shape optimization method over a range of flight conditions.

  12. Longitudinal aerodynamic characteristics of a wing-winglet model designed at M = 0.8, C sub L = 0.4 using linear aerodynamic theory

    NASA Technical Reports Server (NTRS)

    Kuhlman, J. M.

    1983-01-01

    Wind tunnel test results have been presented herein for a subsonic transport type wing fitted with winglets. Wind planform was chosen to be representative of wings used on current jet transport aircraft, while wing and winglet camber surfaces were designed using two different linear aerodynamic design methods. The purpose of the wind tunnel investigation was to determine the effectiveness of these linear aerodynamic design computer codes in designing a non-planar transport configuration which would cruise efficiently. The design lift coefficient was chosen to be 0.4, at a design Mach number of 0.8. Force and limited pressure data were obtained for the basic wing, and for the wing fitted with the two different winglet designs, at Mach numbers of 0.60, 0.70, 0.75 and 0.80 over an angle of attack range of -2 to +6 degrees, at zero sideslip. The data have been presented without analysis to expedite publication.

  13. SRB ascent aerodynamic heating design criteria reduction study, volume 1

    NASA Technical Reports Server (NTRS)

    Crain, W. K.; Frost, C. L.; Engel, C. D.

    1989-01-01

    An independent set of solid rocket booster (SRB) convective ascent design environments were produced which would serve as a check on the Rockwell IVBC-3 environments used to design the ascent phase of flight. In addition, support was provided for lowering the design environments such that Thermal Protection System (TPS), based on conservative estimates, could be removed leading to a reduction in SRB refurbishment time and cost. Ascent convective heating rates and loads were generated at locations in the SRB where lowering the thermal environment would impact the TPS design. The ascent thermal environments are documented along with the wind tunnel/flight test data base used as well as the trajectory and environment generation methodology. Methodology, as well as, environment summaries compared to the 1980 Design and Rockwell IVBC-3 Design Environment are presented in this volume, 1.

  14. Aerodynamic Design Criteria for Class 8 Heavy Vehicles Trailer Base Devices to Attain Optimum Performance

    SciTech Connect

    Salari, K; Ortega, J

    2010-12-13

    Lawrence Livermore National Laboratory (LLNL) as part of its Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE), and Vehicle Technologies Program (VTP) effort has investigated class 8 tractor-trailer aerodynamics for many years. This effort has identified many drag producing flow structures around the heavy vehicles and also has designed and tested many new active and passive drag reduction techniques and concepts for significant on the road fuel economy improvements. As part of this effort a database of experimental, computational, and conceptual design for aerodynamic drag reduction devices has been established. The objective of this report is to provide design guidance for trailer base devices to improve their aerodynamic performance. These devices are commonly referred to as boattails, base flaps, tail devices, and etc. The information provided here is based on past research and our most recent full-scale experimental investigations in collaboration with Navistar Inc. Additional supporting data from LLNL/Navistar wind tunnel, track test, and on the road test will be published soon. The trailer base devices can be identified by 4 flat panels that are attached to the rear edges of the trailer base to form a closed cavity. These devices have been engineered in many different forms such as, inflatable and non-inflatable, 3 and 4-sided, closed and open cavity, and etc. The following is an in-depth discussion with some recommendations, based on existing data and current research activities, of changes that could be made to these devices to improve their aerodynamic performance. There are 6 primary factors that could influence the aerodynamic performance of trailer base devices: (1) Deflection angle; (2) Boattail length; (3) Sealing of edges and corners; (4) 3 versus 4-sided, Position of the 4th plate; (5) Boattail vertical extension, Skirt - boattail transition; and (6) Closed versus open cavity.

  15. Machine learning paradigms in design optimization: Applications in turbine aerodynamic design

    NASA Astrophysics Data System (ADS)

    Goel, Sanjay

    Mechanisms of incorporating machine learning paradigms in design optimization have been investigated in the current research. The primary focus of the work is on machine learning algorithms which use computational models that are analogous to the hypothesized principles of natural or biological learning. Examples from structural and aerodynamic optimization have been used to demonstrate the potential of the proposed schemes. The first strategy examined in the current work seeks to improve the convergence of optimization problems by pruning the search space of weak variables. Such variables are identified by learning from a database of existing designs using neural networks. By using clustering techniques, different sets of weak variables are identified in different regions of the design space. Parameter sensitivity information obtained in the process of identifying weak variables provides accurate heuristics for formulating design rules. The impact of this methodology on obtaining converged designs has been investigated for a turbine design problem. Optimization results from a three-stage power turbine and an aircraft engine turbine are presented in this thesis. The second scheme is an evolutionary design optimization technique which gets progressively 'smarter' during the optimization process by learning from computed domain knowledge. This technique employs adaptive learning mechanisms (classifiers) which recognize the influence of the design variables on the problem solution and then generalize them to dynamically create or change design rules during optimization. This technique, when applied to a constrained optimization problem, shows progressive improvement in convergence of search, as successive generations of rules evolve by learning from the environment. To investigate this methodology, a truss optimization problem is solved with an objective of minimizing the truss weight subject to stress constraints in the truss members. A distinct convergent trend is

  16. Simultaneous Aerodynamic and Structural Design Optimization (SASDO) for a 3-D Wing

    NASA Technical Reports Server (NTRS)

    Gumbert, Clyde R.; Hou, Gene J.-W.; Newman, Perry A.

    2001-01-01

    The formulation and implementation of an optimization method called Simultaneous Aerodynamic and Structural Design Optimization (SASDO) is shown as an extension of the Simultaneous Aerodynamic Analysis and Design Optimization (SAADO) method. It is extended by the inclusion of structure element sizing parameters as design variables and Finite Element Method (FEM) analysis responses as constraints. The method aims to reduce the computational expense. incurred in performing shape and sizing optimization using state-of-the-art Computational Fluid Dynamics (CFD) flow analysis, FEM structural analysis and sensitivity analysis tools. SASDO is applied to a simple. isolated, 3-D wing in inviscid flow. Results show that the method finds the saine local optimum as a conventional optimization method with some reduction in the computational cost and without significant modifications; to the analysis tools.

  17. Thermal Analysis and Design of Multi-layer Insulation for Re-entry Aerodynamic Heating

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran

    2001-01-01

    The combined radiation/conduction heat transfer in high-temperature multi-layer insulations was modeled using a finite volume numerical model. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements, and by transient thermal tests simulating re-entry aerodynamic heating conditions. A design of experiments technique was used to investigate optimum design of multi-layer insulations for re-entry aerodynamic heating. It was found that use of 2 mm foil spacing and locating the foils near the hot boundary with the top foil 2 mm away from the hot boundary resulted in the most effective insulation design. A 76.2 mm thick multi-layer insulation using 1, 4, or 16 foils resulted in 2.9, 7.2, or 22.2 percent mass per unit area savings compared to a fibrous insulation sample at the same thickness, respectively.

  18. Performance and Design Investigation of Heavy Lift Tiltrotor with Aerodynamic Interference Effects

    NASA Technical Reports Server (NTRS)

    Yeo, Yyeonsoo; Johnson, Wayne

    2007-01-01

    The aerodynamic interference effects on tiltrotor performance in cruise are investigated using comprehensive calculations, to better understand the physics and to quantify the effects on the aircraft design. Performance calculations were conducted for 146,600-lb conventional and quad tiltrotors, which are to cruise at 300 knots at 4000 ft/95 deg F condition. A parametric study was conducted to understand the effects of design parameters on the performance of the aircraft. Aerodynamic interference improves the aircraft lift-to-drag ratio of the baseline conventional tiltrotor. However, interference degrades the aircraft performance of the baseline quad tiltrotor, due mostly to the unfavorable effects from the front wing to the rear wing. A reduction of rotor tip speed increased the aircraft lift-to-drag ratio the most among the design parameters investigated.

  19. SRB ascent aerodynamic heating design criteria reduction study, volume 2

    NASA Technical Reports Server (NTRS)

    Crain, W. K.; Frost, C. L.; Engel, C. D.

    1989-01-01

    Data are presented for the wind tunnel interference heating factor data base, the timewise tabulated ascent design environments, and the timewise plotted environments comparing the REMTECH results to the Rockwell RI-IVBC-3 results.

  20. Optimal Aerodynamic Design of Conventional and Coaxial Helicopter Rotors in Hover and Forward Flight

    NASA Astrophysics Data System (ADS)

    Giovanetti, Eli B.

    ) and the wake as contracting cylindrical vortex sheets that we represent as discrete vortex rings. We assume the system is axisymmetric and steady in time, and solve for the wake position that results in all vortex sheets being aligned with the streamlines of the flow field via Newton iteration. We show that the singularity that occurs where the vortex sheet terminates at the edge of the actuator disk is resolved through the formation of a 45° logarithmic spiral in hover, which results in a non-uniform inflow, particularly near the edge of the disk where the flow is entirely reversed, as originally hypothesized by previous authors. We also quantify the mutual interference of coaxial actuator disks of various axial spacing. Finally, we combine our forward flight optimization procedure and the Blade Element Momentum Theory hover optimization to form a variational approach to the multipoint aerodynamic design optimization of conventional and coaxial helicopter rotors. The resulting nonlinear constrained optimization problem may be used to map the Pareto frontier, i.e., the set of rotor designs for which it is not possible to improve upon the performance in one flight condition without degrading performance in the other. We show that for both conventional and coaxial rotors analyzed in hover and high speed flight, a substantial tradeoff in performance must be made between the two flight conditions. Finally, computational results demonstrate that higher harmonic control is able to improve the Pareto efficiency for both conventional and coaxial rotors.

  1. Nonlinear aerodynamics and the design of wing tips

    NASA Technical Reports Server (NTRS)

    Kroo, Ilan; Wakayama, Sean

    1992-01-01

    This report describes results of research conducted from April 1991 through March 1992. The general objective was to improve an existing wing optimization method, and apply the method to specific problems of interest. The method, while a valuable tool for wing tip design studies, can be applied to more general problems, and has been applied to some of these other problems during its development. Specific goals that were accomplished are listed and explained in more detail in the report. First, improvements were made to the portability and control flow of the existing code. The major iteration loop dealing with structural design was sped up and an alternate approach, using the optimizer to do structural sizing, was studied. Second, analysis methods were improved in the areas of structural and high lift modeling. The structural method was revised to give total wing weight and verified against data for particular commercial aircraft. The high lift analysis was improved to provide reasonable estimates of C(sub L max) in the flaps down condition. These improvements enabled making wing area a design variable, where it had been a fixed variable in the original method. Third, the method was applied to the design of wings for a Learjet. Rough studies were done to determine the effects of laminar flow design on wing shape. Finally, studies on wingtip shape were begun.

  2. Nonlinear Aerodynamics and the Design of Wing Tips

    NASA Technical Reports Server (NTRS)

    Kroo, Ilan

    1991-01-01

    The analysis and design of wing tips for fixed wing and rotary wing aircraft still remains part art, part science. Although the design of airfoil sections and basic planform geometry is well developed, the tip regions require more detailed consideration. This is important because of the strong impact of wing tip flow on wing drag; although the tip region constitutes a small portion of the wing, its effect on the drag can be significant. The induced drag of a wing is, for a given lift and speed, inversely proportional to the square of the wing span. Concepts are proposed as a means of reducing drag. Modern computational methods provide a tool for studying these issues in greater detail. The purpose of the current research program is to improve the understanding of the fundamental issues involved in the design of wing tips and to develop the range of computational and experimental tools needed for further study of these ideas.

  3. Computational methods of robust controller design for aerodynamic flutter suppression

    NASA Technical Reports Server (NTRS)

    Anderson, L. R.

    1981-01-01

    The development of Riccati iteration, a tool for the design and analysis of linear control systems is examined. First, Riccati iteration is applied to the problem of pole placement and order reduction in two-time scale control systems. Order reduction, yielding a good approximation to the original system, is demonstrated using a 16th order linear model of a turbofan engine. Next, a numerical method for solving the Riccati equation is presented and demonstrated for a set of eighth order random examples. A literature review of robust controller design methods follows which includes a number of methods for reducing the trajectory and performance index sensitivity in linear regulators. Lastly, robust controller design for large parameter variations is discussed.

  4. An approach to constrained aerodynamic design with application to airfoils

    NASA Technical Reports Server (NTRS)

    Campbell, Richard L.

    1992-01-01

    An approach was developed for incorporating flow and geometric constraints into the Direct Iterative Surface Curvature (DISC) design method. In this approach, an initial target pressure distribution is developed using a set of control points. The chordwise locations and pressure levels of these points are initially estimated either from empirical relationships and observed characteristics of pressure distributions for a given class of airfoils or by fitting the points to an existing pressure distribution. These values are then automatically adjusted during the design process to satisfy the flow and geometric constraints. The flow constraints currently available are lift, wave drag, pitching moment, pressure gradient, and local pressure levels. The geometric constraint options include maximum thickness, local thickness, leading-edge radius, and a 'glove' constraint involving inner and outer bounding surfaces. This design method was also extended to include the successive constraint release (SCR) approach to constrained minimization.

  5. Nonlinear potential analysis techniques for supersonic aerodynamic design

    NASA Technical Reports Server (NTRS)

    Shankar, V.; Szema, K. Y.

    1985-01-01

    A numerical method based on the conservation form of the full potential equation has been applied to the problem of three-dimensional supersonic flows with embedded subsonic regions. The governing equation is cast in a nonorthogonal coordinate system, and the theory of characteristics is used to accurately monitor the type-dependent flow field. A conservative switching scheme is employed to transition from the supersonic marching procedure to a subsonic relaxation algorithm and vice versa. The newly developed computer program can handle arbitrary geometries with fuselage, canard, wing, flow through nacelle, vertical tail and wake components at combined angles of attack and sideslip. Results are obtained for a variety of configurations that include a Langley advanced fighter concept with fuselage centerline nacelle, Rockwell's Advanced Tactical Fighter (ATF) with wing mounted nacelles, and the Shuttle Orbiter configuration. Comparisons with available experiments were good.

  6. Aerodynamic design and investigation of a mixed flow compressor stage

    NASA Astrophysics Data System (ADS)

    Eisenlohr, Gernot; Benfer, Friedrich Wilhelm

    1994-03-01

    Topic of this contribution is a single stage mixed flow compressor with 6:1 pressure ratio, which is under development as a component for a turbojet. Primary design aim for the stage was to achieve minimum frontal area at a high efficiency level. Excerpts of the considerations and calculations for determining the design rotational speed and the main dimensions of this mixed flow compressor stage are presented first. Some explanations concerning the definition of the meridional contours and the generation of the blading are given, supplemented by several results of the impeller flow calculations. After a brief description of the test rig and its instrumentation, the measured impeller characteristics are presented. They show that the impeller meets its design pressure ratio and exceeds the efficiency target. For selected operating points the measured pressure distributions along the impeller outer contour are compared with the predicted static pressure rise. The discussions of the test results closes with the measured mixed flow compressor map which reveals that the overall stage performance does not fully meet the design goals, mainly because of high losses in the diffusing system.

  7. Intermediate experimental vehicle, ESA program aerodynamics-aerothermodynamics key technologies for spacecraft design and successful flight

    NASA Astrophysics Data System (ADS)

    Dutheil, Sylvain; Pibarot, Julien; Tran, Dac; Vallee, Jean-Jacques; Tribot, Jean-Pierre

    2016-07-01

    With the aim of placing Europe among the world's space players in the strategic area of atmospheric re-entry, several studies on experimental vehicle concepts and improvements of critical re-entry technologies have paved the way for the flight of an experimental space craft. The successful flight of the Intermediate eXperimental Vehicle (IXV), under ESA's Future Launchers Preparatory Programme (FLPP), is definitively a significant step forward from the Atmospheric Reentry Demonstrator flight (1998), establishing Europe as a key player in this field. The IXV project objectives were the design, development, manufacture and ground and flight verification of an autonomous European lifting and aerodynamically controlled reentry system, which is highly flexible and maneuverable. The paper presents, the role of aerodynamics aerothermodynamics as part of the key technologies for designing an atmospheric re-entry spacecraft and securing a successful flight.

  8. Simultaneous Aerodynamic Analysis and Design Optimization (SAADO) for a 3-D Flexible Wing

    NASA Technical Reports Server (NTRS)

    Gumbert, Clyde R.; Hou, Gene J.-W.

    2001-01-01

    The formulation and implementation of an optimization method called Simultaneous Aerodynamic Analysis and Design Optimization (SAADO) are extended from single discipline analysis (aerodynamics only) to multidisciplinary analysis - in this case, static aero-structural analysis - and applied to a simple 3-D wing problem. The method aims to reduce the computational expense incurred in performing shape optimization using state-of-the-art Computational Fluid Dynamics (CFD) flow analysis, Finite Element Method (FEM) structural analysis and sensitivity analysis tools. Results for this small problem show that the method reaches the same local optimum as conventional optimization. However, unlike its application to the win,, (single discipline analysis), the method. as I implemented here, may not show significant reduction in the computational cost. Similar reductions were seen in the two-design-variable (DV) problem results but not in the 8-DV results given here.

  9. Aerodynamic Design of Axial-flow Compressors. Volume III

    NASA Technical Reports Server (NTRS)

    Johnson, Irving A; Bullock, Robert O; Graham, Robert W; Costilow, Eleanor L; Huppert, Merle C; Benser, William A; Herzig, Howard Z; Hansen, Arthur G; Jackson, Robert J; Yohner, Peggy L; Dugan, Ames F , Jr

    1956-01-01

    Chapters XI to XIII concern the unsteady compressor operation arising when compressor blade elements stall. The fields of compressor stall and surge are reviewed in Chapters XI and XII, respectively. The part-speed operating problem in high-pressure-ratio multistage axial-flow compressors is analyzed in Chapter XIII. Chapter XIV summarizes design methods and theories that extend beyond the simplified two-dimensional approach used previously in the report. Chapter XV extends this three-dimensional treatment by summarizing the literature on secondary flows and boundary layer effects. Charts for determining the effects of errors in design parameters and experimental measurements on compressor performance are given in Chapters XVI. Chapter XVII reviews existing literature on compressor and turbine matching techniques.

  10. Core compressor exit stage study. 1: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Burdsall, E. A.; Canal, E., Jr.; Lyons, K. A.

    1979-01-01

    The effect of aspect ratio on the performance of core compressor exit stages was demonstrated using two three stage, highly loaded, core compressors. Aspect ratio was identified as having a strong influence on compressors endwall loss. Both compressors simulated the last three stages of an advanced eight stage core compressor and were designed with the same 0.915 hub/tip ratio, 4.30 kg/sec (9.47 1bm/sec) inlet corrected flow, and 167 m/sec (547 ft/sec) corrected mean wheel speed. The first compressor had an aspect ratio of 0.81 and an overall pressure ratio of 1.357 at a design adiabatic efficiency of 88.3% with an average diffusion factor or 0.529. The aspect ratio of the second compressor was 1.22 with an overall pressure ratio of 1.324 at a design adiabatic efficiency of 88.7% with an average diffusion factor of 0.491.

  11. A computational system for aerodynamic design and analysis of supersonic aircraft. Part 2: User's manual

    NASA Technical Reports Server (NTRS)

    Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

    1976-01-01

    An integrated system of computer programs was developed for the design and analysis of supersonic configurations. The system uses linearized theory methods for the calculation of surface pressures and supersonic area rule concepts in combination with linearized theory for calculation of aerodynamic force coefficients. Interactive graphics are optional at the user's request. This user's manual contains a description of the system, an explanation of its usage, the input definition, and example output.

  12. Integrating aerodynamic surface modeling for computational fluid dynamics with computer aided structural analysis, design, and manufacturing

    NASA Technical Reports Server (NTRS)

    Thorp, Scott A.

    1992-01-01

    This presentation will discuss the development of a NASA Geometry Exchange Specification for transferring aerodynamic surface geometry between LeRC systems and grid generation software used for computational fluid dynamics research. The proposed specification is based on a subset of the Initial Graphics Exchange Specification (IGES). The presentation will include discussion of how the NASA-IGES standard will accommodate improved computer aided design inspection methods and reverse engineering techniques currently being developed. The presentation is in viewgraph format.

  13. DOE's effort to reduce truck aerodynamic drag : joint experiments and computations lead to smart design.

    SciTech Connect

    Yaste, David M; Salari, Kambiz; Hammache, Mustapha; Browand, Fred; Pointer, W. David; Ortega, Jason M.; McCallen, Rose; Walker, Stephen M; Heineck, James T; Hassan, Basil; Roy, Christopher John; Storms, B.; Satran, D.; Ross, James; Englar, Robert; Chatalain, Philippe; Rubel, Mike; Leonard, Anthony; Hsu, Tsu-Ya; DeChant, Lawrence Justin.

    2004-06-01

    At 70 miles per hour, overcoming aerodynamic drag represents about 65% of the total energy expenditure for a typical heavy truck vehicle. The goal of this US Department of Energy supported consortium is to establish a clear understanding of the drag producing flow phenomena. This is being accomplished through joint experiments and computations, leading to the smart design of drag reducing devices. This paper will describe our objective and approach, provide an overview of our efforts and accomplishments, and discuss our future direction.

  14. DOE's Effort to Reduce Truck Aerodynamic Drag-Joint Experiments and Computations Lead to Smart Design

    SciTech Connect

    McCallen, R; Salari, K; Ortega, J; DeChant, L; Hassan, B; Roy, C; Pointer, W; Browand, F; Hammache, M; Hsu, T; Leonard, A; Rubel, M; Chatalain, P; Englar, R; Ross, J; Satran, D; Heineck, J; Walker, S; Yaste, D; Storms, B

    2004-06-17

    At 70 miles per hour, overcoming aerodynamic drag represents about 65% of the total energy expenditure for a typical heavy truck vehicle. The goal of this US Department of Energy supported consortium is to establish a clear understanding of the drag producing flow phenomena. This is being accomplished through joint experiments and computations, leading to the 'smart' design of drag reducing devices. This paper will describe our objective and approach, provide an overview of our efforts and accomplishments, and discuss our future direction.

  15. Aerodynamic design and analysis system for supersonic aircraft. Part 1: General description and theoretical development

    NASA Technical Reports Server (NTRS)

    Middleton, W. D.; Lundry, J. L.

    1975-01-01

    An integrated system of computer programs has been developed for the design and analysis of supersonic configurations. The system uses linearized theory methods for the calculation of surface pressures and supersonic area rule concepts in combination with linearized theory for calculation of aerodynamic force coefficients. Interactive graphics are optional at the user's request. This part presents a general description of the system and describes the theoretical methods used.

  16. Visualization in the Design of Modern Aircraft Aerodynamics

    NASA Technical Reports Server (NTRS)

    Bryson, Steve; Kutler, Paul (Technical Monitor)

    1997-01-01

    Modem aircraft design involves study of airflow through both windtunnel testing and computer simulation. These computer simulations result in often very large and complex sets of numbers, which contain information critical to the aircrafts performance. This talk will describe how visualization is used to understand these simulations, using a variety of techniques including low-level analysis such as simulated particles, high-level feature detection, and virtual-reality-based techniques for exploration. We will focus on the challenges of extremely large data sets, interactive performance, and information extraction. The talk will close with a vision of the future including the integration of simulation and visualization.

  17. Simulation-based aerodynamic design of high-lift devices in ground effect

    NASA Astrophysics Data System (ADS)

    Melvin, Arron Hector

    2007-12-01

    A simulation-based aerodynamic design tool is developed for multi-element high-lift airfoils operating in ground effect. A control theory approach is adopted, using the compressible Navier-Stokes equations as the basis for viscous design of airfoil element shapes and relative positioning. Particular considerations of aerodynamic design, high-lift systems, and the ground effect are described, and the suitability of aerodynamic shape optimization of such systems is discussed. The model of fluid flow and its discretization for solution on digital computers is investigated. A cell-centered finite-volume explicit multigrid method is used to solve both the flow and adjoint systems utilizing structured multiblock meshes. The adjoint equations for shape optimization are developed using a continuous adjoint formulation, and implemented with a moving ground boundary condition for the first time. A suite of test cases verified and validated the numerical algorithms and implementation. Realistic case studies were performed, demonstrating significant performance improvements over the baseline configurations. These included two free-air multi-element airfoil drag minimizations, and in addition two inverted two-element airfoil drag minimizations in ground effect.

  18. An Efficient Multiblock Method for Aerodynamic Analysis and Design on Distributed Memory Systems

    NASA Technical Reports Server (NTRS)

    Reuther, James; Alonso, Juan Jose; Vassberg, John C.; Jameson, Antony; Martinelli, Luigi

    1997-01-01

    The work presented in this paper describes the application of a multiblock gridding strategy to the solution of aerodynamic design optimization problems involving complex configurations. The design process is parallelized using the MPI (Message Passing Interface) Standard such that it can be efficiently run on a variety of distributed memory systems ranging from traditional parallel computers to networks of workstations. Substantial improvements to the parallel performance of the baseline method are presented, with particular attention to their impact on the scalability of the program as a function of the mesh size. Drag minimization calculations at a fixed coefficient of lift are presented for a business jet configuration that includes the wing, body, pylon, aft-mounted nacelle, and vertical and horizontal tails. An aerodynamic design optimization is performed with both the Euler and Reynolds Averaged Navier-Stokes (RANS) equations governing the flow solution and the results are compared. These sample calculations establish the feasibility of efficient aerodynamic optimization of complete aircraft configurations using the RANS equations as the flow model. There still exists, however, the need for detailed studies of the importance of a true viscous adjoint method which holds the promise of tackling the minimization of not only the wave and induced components of drag, but also the viscous drag.

  19. Application of Reduced Order Transonic Aerodynamic Influence Coefficient Matrix for Design Optimization

    NASA Technical Reports Server (NTRS)

    Pak, Chan-gi; Li, Wesley W.

    2009-01-01

    Supporting the Aeronautics Research Mission Directorate guidelines, the National Aeronautics and Space Administration [NASA] Dryden Flight Research Center is developing a multidisciplinary design, analysis, and optimization [MDAO] tool. This tool will leverage existing tools and practices, and allow the easy integration and adoption of new state-of-the-art software. Today s modern aircraft designs in transonic speed are a challenging task due to the computation time required for the unsteady aeroelastic analysis using a Computational Fluid Dynamics [CFD] code. Design approaches in this speed regime are mainly based on the manual trial and error. Because of the time required for unsteady CFD computations in time-domain, this will considerably slow down the whole design process. These analyses are usually performed repeatedly to optimize the final design. As a result, there is considerable motivation to be able to perform aeroelastic calculations more quickly and inexpensively. This paper will describe the development of unsteady transonic aeroelastic design methodology for design optimization using reduced modeling method and unsteady aerodynamic approximation. The method requires the unsteady transonic aerodynamics be represented in the frequency or Laplace domain. Dynamically linear assumption is used for creating Aerodynamic Influence Coefficient [AIC] matrices in transonic speed regime. Unsteady CFD computations are needed for the important columns of an AIC matrix which corresponded to the primary modes for the flutter. Order reduction techniques, such as Guyan reduction and improved reduction system, are used to reduce the size of problem transonic flutter can be found by the classic methods, such as Rational function approximation, p-k, p, root-locus etc. Such a methodology could be incorporated into MDAO tool for design optimization at a reasonable computational cost. The proposed technique is verified using the Aerostructures Test Wing 2 actually designed

  20. Challenges and Progress in Aerodynamic Design of Hybrid Wingbody Aircraft with Embedded Engines

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Kim, Hyoungjin; Liou, May-Fun

    2016-01-01

    We summarize the contributions to high-fidelity capabilities for analysis and design of hybrid wingbody (HWB) configurations considered by NASA. Specifically, we focus on the embedded propulsion concepts of the N2-B and N3-X configurations, some of the future concepts seriously investigated by the NASA Fixed Wing Project. The objective is to develop the capability to compute the integrated propulsion and airframe system realistically in geometry and accurately in flow physics. In particular, the propulsion system (including the entire engine core-compressor, combustor, and turbine stages) is vastly more difficult and costly to simulate with the same level of fidelity as the external aerodynamics. Hence, we develop an accurate modeling approach that retains important physical parameters relevant to aerodynamic and propulsion analyses for evaluating the HWB concepts. Having the analytical capabilities at our disposal, concerns and issues that were considered to be critical for the HWB concepts can now be assessed reliably and systematically; assumptions invoked by previous studies were found to have serious consequences in our study. During this task, we establish firmly that aerodynamic analysis of a HWB concept without including installation of the propulsion system is far from realistic and can be misleading. Challenges in delivering the often-cited advantages that belong to the HWB are the focus of our study and are emphasized in this report. We have attempted to address these challenges and have had successes, which are summarized here. Some can have broad implications, such as the concept of flow conditioning for reducing flow distortion and the modeling of fan stages. The design optimization capability developed for improving the aerodynamic characteristics of the baseline HWB configurations is general and can be employed for other applications. Further improvement of the N3-X configuration can be expected by expanding the design space. Finally, the support of

  1. Aerodynamic design and analysis of the AST-200 supersonic transport configuration concept

    NASA Technical Reports Server (NTRS)

    Walkley, K. B.; Martin, G. L.

    1979-01-01

    The design and analysis of a supersonic transport configuration was conducted using linear theory methods in conjunction with appropriate constraints. Wing optimization centered on the determination of the required twist and camber and proper integration of the wing and fuselage. Also included in the design are aerodynamic refinements to the baseline wing thickness distribution and nacelle shape. Analysis to the baseline and revised configurations indicated an improvement in lift-to-drag ratio of 0.36 at the Mach 2.7 cruise condition. Validation of the design is planned through supersonic wing tunnel tests.

  2. The research progress on Hodograph Method of aerodynamic design at Tsinghua University

    NASA Technical Reports Server (NTRS)

    Chen, Zuoyi; Guo, Jingrong

    1991-01-01

    Progress in the use of the Hodograph method of aerodynamic design is discussed. It was found that there are some restricted conditions in the application of Hodograph design to transonic turbine and compressor cascades. The Hodograph method is suitable not only to the transonic turbine cascade but also to the transonic compressor cascade. The three dimensional Hodograph method will be developed after obtaining the basic equation for the three dimensional Hodograph method. As an example of the Hodograph method, the use of the method to design a transonic turbine and compressor cascade is discussed.

  3. Optimum design of hydrostatic journal bearings. Part III. Design procedure

    SciTech Connect

    El-Sherbiny, M.; Salem, F.; El-Hefnawy, N.

    1986-01-01

    A systematic design procedure is presented which can be used by engineers and designers for designing hydrostatic journal bearings with minimum power consumption. Design charts correlating the optimum design variables are presented. These are obtained from an optimization study minimizing the total power consumed by the pump and the power dissipating in viscous shearing within the bearing area. A design example is presented to demonstrate the applications of the proposed procedure.

  4. Aerodynamic characteristics of some lifting reentry concepts applicable to transatmospheric vehicle design studies

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1984-01-01

    The aerodynamic characteristics of some lifting reentry concepts are examined with a view to the applicability of such concepts to the design of possible transatmospheric vehicles (TAV). A considerable amount of research has been done in past years with vehicle concepts suitable for manned atmospheric-entry, atmospheric flight, and landing. Some of the features of these concepts that permit flight in or out of the atmosphere with maneuver capability should be useful in the mission requirements of TAV's. The concepts illustrated include some hypersonic-body shapes with and without variable geometry surfaces, and a blunt lifting-body configuration. The merits of these concepts relative to the aerodynamic behavior of a TAV are discussed.

  5. Reductions in vehicle fuel consumption due to refinements in aerodynamic design. [for trailer trucks

    NASA Technical Reports Server (NTRS)

    Saltzman, E. J.

    1979-01-01

    Over-the-highway fuel consumption and coastdown drag tests were performed on cab-over-engine, van type trailer trucks and modifications of these vehicles incorporating refinements in aerodynamic design. In addition, 1/25-scale models of these configurations, and derivatives of these configurations were tested in a wind tunnel to determine the effects of wind on the magnitude of the benefits that aerodynamic refinements can provide. The results of these tests are presented for a vehicle incorporating major redesign features and for a relatively simple add-on modification. These results include projected fuel savings on the basis of annual savings per vehicle year as well as probable nationwide fuel savings.

  6. The Modern Design of Experiments for Configuration Aerodynamics: A Case Study

    NASA Technical Reports Server (NTRS)

    DeLoach, Richard

    2006-01-01

    The effects of slowly varying and persisting covariate effects on the accuracy and precision of experimental result is reviewed, as is the rationale for run-order randomization as a quality assurance tactic employed in the Modern Design of Experiments (MDOE) to defend against such effects. Considerable analytical complexity is introduced by restrictions on randomization in configuration aerodynamics tests because they involve hard-to-change configuration variables that cannot be randomized conveniently. Tradeoffs are examined between quality and productivity associated with varying degrees of rigor in accounting for such randomization restrictions. Certain characteristics of a configuration aerodynamics test are considered that may justify a relaxed accounting for randomization restrictions to achieve a significant reduction in analytical complexity with a comparably negligible adverse impact on the validity of the experimental results.

  7. Design and aerodynamic performance evaluation of a high-work mixed flow turbine stage

    NASA Technical Reports Server (NTRS)

    Neri, Remo N.; Elliott, Thomas J.; Marsh, David N.; Civinskas, Kestutis C.

    1994-01-01

    As axial and radial turbine designs have been pushed to their aerothermodynamic and mechanical limits, the mixed-flow turbine (MFT) concept has been projected to offer performance and durability improvements, especially when ceramic materials are considered. The objective of this NASA/U.S. Army sponsored mixed-flow turbine (AMFT) program was to determine the level of performance attainable with MFT technology within the mechanical constraints of 1997 projected ceramic material properties. The MFT geometry is similar to a radial turbine, exhibiting a large radius change from inlet to exit, but differing in that the inlet flowpath is not purely radial, nor axial, but mixed; it is the inlet geometry that gives rise to the name 'mixed-flow'. The 'mixed' orientation of the turbine inlet offers several advantages over radial designs by allowing a nonzero inlet blade angle yet maintaining radial-element blades. The oblique inlet not only improves the particle-impact survivability of the design, but improves the aerodynamic performance by reducing the incidence at the blade inlet. The difficulty, however, of using mixed-flow geometry lies in the scarcity of detailed data and documented design experience. This paper reports the design of a MFT stage designed with the intent to maximize aerodynamic performance by optimizing design parameters such as stage reaction, rotor incidence, flowpath shape, blade shape, vane geometry, and airfoil counts using 2-D, 3-D inviscid, and 3-D viscous computational fluid dynamics code. The aerodynamic optimization was accomplished while maintaining mechanical integrity with respect to vibration and stress levels in the rotor. A full-scale cold-flow rig test was performed with metallic hardware fabricated to the specifications of the hot ceramic geometry to evaluate the stage performance.

  8. Aerodynamic study of a turbine designed for a small low-cost turbofan engine

    NASA Technical Reports Server (NTRS)

    Kofskey, M. G.; Nusbaum, W. J.

    1972-01-01

    An eight inch mean diameter two-stage turbine was experimentally investigated over a range of speeds from 0 to 110 percent of equivalent design speed and over a range of pressure ratios from 2.2 to 4.2. The principal results indicated that the performance level was substantially higher than that assumed in the design. As part of the program to reduce manufacturing costs, the first stage blading was reduced in thickness for ease in coining. Tests of the modified blades indicated that the aerodynamic performance of a stator or rotor blade with a large amount of reaction was effected very little by a significant change of the pressure surface.

  9. Aerodynamic Design of a Propeller for High-Altitude Balloon Trajectory Control

    NASA Technical Reports Server (NTRS)

    Eppler, Richard; Somers, Dan M.

    2012-01-01

    The aerodynamic design of a propeller for the trajectory control of a high-altitude, scientific balloon has been performed using theoretical methods developed especially for such applications. The methods are described. Optimum, nonlinear chord and twist distributions have been developed in conjunction with the design of a family of airfoils, the SE403, SE404, and SE405, for the propeller. The very low Reynolds numbers along the propeller blade fall in a range that has yet to be rigorously investigated, either experimentally or theoretically.

  10. A performance index approach to aerodynamic design with the use of analysis codes only

    NASA Technical Reports Server (NTRS)

    Barger, Raymond L.; Moitra, Anutosh

    1988-01-01

    A method is described for designing an aerodynamic configuration for a specified performance vector, based on results from several similar, but not identical, trial configurations, each defined by a geometry parameter vector. The theory shows the method effective provided that: (1) the results for the trial configuration provide sufficient variation so that a linear combination of them approximates the specified performance; and (2) the difference between the performance vectors (including the specifed performance) are sufficiently small that the linearity assumption of sensitivity analysis applies to the differences. A computed example describes the design of a high supersonic Mach number missile wing body configuration based on results from a set of four trial configurations.

  11. Physical Insights, Steady Aerodynamic Effects, and a Design Tool for Low-Pressure Turbine Flutter

    NASA Astrophysics Data System (ADS)

    Waite, Joshua Joseph

    The successful, efficient, and safe turbine design requires a thorough understanding of the underlying physical phenomena. This research investigates the physical understanding and parameters highly correlated to flutter, an aeroelastic instability prevalent among low pressure turbine (LPT) blades in both aircraft engines and power turbines. The modern way of determining whether a certain cascade of LPT blades is susceptible to flutter is through time-expensive computational fluid dynamics (CFD) codes. These codes converge to solution satisfying the Eulerian conservation equations subject to the boundary conditions of a nodal domain consisting fluid and solid wall particles. Most detailed CFD codes are accompanied by cryptic turbulence models, meticulous grid constructions, and elegant boundary condition enforcements all with one goal in mind: determine the sign (and therefore stability) of the aerodynamic damping. The main question being asked by the aeroelastician, "is it positive or negative?'' This type of thought-process eventually gives rise to a black-box effect, leaving physical understanding behind. Therefore, the first part of this research aims to understand and reveal the physics behind LPT flutter in addition to several related topics including acoustic resonance effects. A percentage of this initial numerical investigation is completed using an influence coefficient approach to study the variation the work-per-cycle contributions of neighboring cascade blades to a reference airfoil. The second part of this research introduces new discoveries regarding the relationship between steady aerodynamic loading and negative aerodynamic damping. Using validated CFD codes as computational wind tunnels, a multitude of low-pressure turbine flutter parameters, such as reduced frequency, mode shape, and interblade phase angle, will be scrutinized across various airfoil geometries and steady operating conditions to reach new design guidelines regarding the influence

  12. Computerized method and system for designing an aerodynamic focusing lens stack

    DOEpatents

    Gard, Eric; Riot, Vincent; Coffee, Keith; Woods, Bruce; Tobias, Herbert; Birch, Jim; Weisgraber, Todd

    2011-11-22

    A computerized method and system for designing an aerodynamic focusing lens stack, using input from a designer related to, for example, particle size range to be considered, characteristics of the gas to be flowed through the system, the upstream temperature and pressure at the top of a first focusing lens, the flow rate through the aerodynamic focusing lens stack equivalent at atmosphere pressure; and a Stokes number range. Based on the design parameters, the method and system determines the total number of focusing lenses and their respective orifice diameters required to focus the particle size range to be considered, by first calculating for the orifice diameter of the first focusing lens in the Stokes formula, and then using that value to determine, in iterative fashion, intermediate flow values which are themselves used to determine the orifice diameters of each succeeding focusing lens in the stack design, with the results being output to a designer. In addition, the Reynolds numbers associated with each focusing lens as well as exit nozzle size may also be determined to enhance the stack design.

  13. SAPHIRE Change Design and Testing Procedure

    SciTech Connect

    Curtis Smith

    2010-02-01

    This document describes the procedure software developers of SAPHIRE follow when adding a new feature or revising an existing capability. This procedure first describes the general approach to changes, and then describes more specific processes. The process stages include design and development, testing, and documentation.

  14. Design procedures for fiber composite box beams

    NASA Technical Reports Server (NTRS)

    Chamis, Cristos C.; Murthy, Pappu L. N.

    1989-01-01

    Step-by-step procedures are described which can be used for the preliminary design of fiber composite box beams subjected to combined loadings. These procedures include a collection of approximate closed-form equations so that all the required calculations can be performed using pocket calculators. Included is an illustrative example of a tapered cantilever box beam subjected to combined loads. The box beam is designed to satisfy strength, displacement, buckling, and frequency requirements.

  15. Creation of a Rapid High-Fidelity Aerodynamics Module for a Multidisciplinary Design Environment

    NASA Technical Reports Server (NTRS)

    Srinivasan, Muktha; Whittecar, William; Edwards, Stephen; Mavris, Dimitri N.

    2012-01-01

    In the traditional aerospace vehicle design process, each successive design phase is accompanied by an increment in the modeling fidelity of the disciplinary analyses being performed. This trend follows a corresponding shrinking of the design space as more and more design decisions are locked in. The correlated increase in knowledge about the design and decrease in design freedom occurs partly because increases in modeling fidelity are usually accompanied by significant increases in the computational expense of performing the analyses. When running high fidelity analyses, it is not usually feasible to explore a large number of variations, and so design space exploration is reserved for conceptual design, and higher fidelity analyses are run only once a specific point design has been selected to carry forward. The designs produced by this traditional process have been recognized as being limited by the uncertainty that is present early on due to the use of lower fidelity analyses. For example, uncertainty in aerodynamics predictions produces uncertainty in trajectory optimization, which can impact overall vehicle sizing. This effect can become more significant when trajectories are being shaped by active constraints. For example, if an optimal trajectory is running up against a normal load factor constraint, inaccuracies in the aerodynamic coefficient predictions can cause a feasible trajectory to be considered infeasible, or vice versa. For this reason, a trade must always be performed between the desired fidelity and the resources available. Apart from this trade between fidelity and computational expense, it is very desirable to use higher fidelity analyses earlier in the design process. A large body of work has been performed to this end, led by efforts in the area of surrogate modeling. In surrogate modeling, an up-front investment is made by running a high fidelity code over a Design of Experiments (DOE); once completed, the DOE data is used to create a

  16. Aerodynamic Performance of Scale-Model Turbofan Outlet Guide Vanes Designed for Low Noise

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher E.

    2001-01-01

    The design of effective new technologies to reduce aircraft propulsion noise is dependent on an understanding of the noise sources and noise generation mechanisms in the modern turbofan engine. In order to more fully understand the physics of noise in a turbofan engine, a comprehensive aeroacoustic wind tunnel test programs was conducted called the 'Source Diagnostic Test.' The text was cooperative effort between NASA and General Electric Aircraft Engines, as part of the NASA Advanced Subsonic Technology Noise Reduction Program. A 1/5-scale model simulator representing the bypass stage of a current technology high bypass ratio turbofan engine was used in the test. The test article consisted of the bypass fan and outlet guide vanes in a flight-type nacelle. The fan used was a medium pressure ratio design with 22 individual, wide chord blades. Three outlet guide vane design configurations were investigated, representing a 54-vane radial Baseline configuration, a 26-vane radial, wide chord Low Count configuration and a 26-vane, wide chord Low Noise configuration with 30 deg of aft sweep. The test was conducted in the NASA Glenn Research Center 9 by 15-Foot Low Speed Wind Tunnel at velocities simulating the takeoff and approach phases of the aircraft flight envelope. The Source Diagnostic Test had several acoustic and aerodynamic technical objectives: (1) establish the performance of a scale model fan selected to represent the current technology turbofan product; (2) assess the performance of the fan stage with each of the three distinct outlet guide vane designs; (3) determine the effect of the outlet guide vane configuration on the fan baseline performance; and (4) conduct detailed flowfield diagnostic surveys, both acoustic and aerodynamic, to characterize and understand the noise generation mechanisms in a turbofan engine. This paper addresses the fan and stage aerodynamic performance results from the Source Diagnostic Test.

  17. Aerodynamic and mechanical design of an 8:1 pressure ratio centrifugal compressor

    NASA Technical Reports Server (NTRS)

    Osborne, C.; Runstadler, P. W., Jr.; Stacy, W. D.

    1974-01-01

    A high-pressure-ratio, low-mass-flow centrifugal compressor stage was designed, fabricated, and tested. The design followed specifications that the stage be representative of state-of-the-art performance and that the stage is to be used as a workhorse compressor for planned experiments using laser Doppler velocimeter equipment. The final design is a 75,000-RPM, 19-blade impeller with an axial inducer and 30 degrees of backward leaning at the impeller tip. The compressor design was tested for two- and/or quasi-three-dimensional aerodynamic and stress characteristics. Critical speed analyses were performed for the high speed rotating impeller assembly. An optimally matched, 17-channel vane island diffuser was also designed and built.

  18. Aerodynamic aircraft design methods and their notable applications: Survey of the activity in Japan

    NASA Technical Reports Server (NTRS)

    Fujii, Kozo; Takanashi, Susumu

    1991-01-01

    An overview of aerodynamic aircraft design methods and their recent applications in Japan is presented. A design code which was developed at the National Aerospace Laboratory (NAL) and is in use now is discussed, hence, most of the examples are the result of the collaborative work between heavy industry and the National Aerospace Laboratory. A wide variety of applications in transonic to supersonic flow regimes are presented. Although design of aircraft elements for external flows are the main focus, some of the internal flow applications are also presented. Recent applications of the design code, using the Navier Stokes and Euler equations in the analysis mode, include the design of HOPE (a space vehicle) and Upper Surface Blowing (USB) aircraft configurations.

  19. On the Use of Parmetric-CAD Systems and Cartesian Methods for Aerodynamic Design

    NASA Technical Reports Server (NTRS)

    Nemec, Marian; Aftosmis, Michael J.; Pulliam, Thomas H.

    2004-01-01

    Automated, high-fidelity tools for aerodynamic design face critical issues in attempting to optimize real-life geometry arid in permitting radical design changes. Success in these areas promises not only significantly shorter design- cycle times, but also superior and unconventional designs. To address these issues, we investigate the use of a parmetric-CAD system in conjunction with an embedded-boundary Cartesian method. Our goal is to combine the modeling capabilities of feature-based CAD with the robustness and flexibility of component-based Cartesian volume-mesh generation for complex geometry problems. We present the development of an automated optimization frame-work with a focus on the deployment of such a CAD-based design approach in a heterogeneous parallel computing environment.

  20. The vehicle design evaluation program - A computer-aided design procedure for transport aircraft

    NASA Technical Reports Server (NTRS)

    Oman, B. H.; Kruse, G. S.; Schrader, O. E.

    1977-01-01

    The vehicle design evaluation program is described. This program is a computer-aided design procedure that provides a vehicle synthesis capability for vehicle sizing, external load analysis, structural analysis, and cost evaluation. The vehicle sizing subprogram provides geometry, weight, and balance data for aircraft using JP, hydrogen, or methane fuels. The structural synthesis subprogram uses a multistation analysis for aerodynamic surfaces and fuselages to develop theoretical weights and geometric dimensions. The parts definition subprogram uses the geometric data from the structural analysis and develops the predicted fabrication dimensions, parts material raw stock buy requirements, and predicted actual weights. The cost analysis subprogram uses detail part data in conjunction with standard hours, realization factors, labor rates, and material data to develop the manufacturing costs. The program is used to evaluate overall design effects on subsonic commercial type aircraft due to parameter variations.

  1. NREL Advanced Research Turbine (ART) Aerodynamic Design of ART-2B Rotor Blades

    SciTech Connect

    Griffin, D.A.

    2000-09-05

    The National Renewable Energy Laboratory (NREL) installed two Advanced Research Turbines (ART) at the National Wind Technology Center near Boulder, Colorado, to use as full-scale test beds for ongoing research efforts, including three-dimensional blade aerodynamics and the effects of various control methods on turbine loads and performance. The Westinghouse WWG-0600 was selected as a baseline configuration for the ART turbines. The first turbine, ART-1, is currently operational and has been used to collect a baseline set of performance and loads data. A second turbine, ART-2A, incorporates several major modifications and may be upgraded further to a configuration designated aRT-2B. Possible features of the ART-2B turbine include a multi-degree of freedom hum and newly designed rotor blades. Global energy concepts, L.L.C. provided engineering support to NREL in designing the components for the ART-2B turbine. This document provides a summary of work performed by GEC on the aerodynamic design of ART-2B rotor blades.

  2. Integrated Design Engineering Analysis (IDEA) Environment - Aerodynamics, Aerothermodynamics, and Thermal Protection System Integration Module

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hilmi N.

    2011-01-01

    This report documents the work performed during from March 2010 October 2011. The Integrated Design and Engineering Analysis (IDEA) environment is a collaborative environment based on an object-oriented, multidisciplinary, distributed environment using the Adaptive Modeling Language (AML) as the underlying framework. This report will focus on describing the work done in the area of extending the aerodynamics, and aerothermodynamics module using S/HABP, CBAERO, PREMIN and LANMIN. It will also detail the work done integrating EXITS as the TPS sizing tool.

  3. Aerodynamic Design Optimization on Unstructured Meshes Using the Navier-Stokes Equations

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Anderson, W. Kyle

    1998-01-01

    A discrete adjoint method is developed and demonstrated for aerodynamic design optimization on unstructured grids. The governing equations are the three-dimensional Reynolds-averaged Navier-Stokes equations coupled with a one-equation turbulence model. A discussion of the numerical implementation of the flow and adjoint equations is presented. Both compressible and incompressible solvers are differentiated and the accuracy of the sensitivity derivatives is verified by comparing with gradients obtained using finite differences. Several simplifying approximations to the complete linearization of the residual are also presented, and the resulting accuracy of the derivatives is examined. Demonstration optimizations for both compressible and incompressible flows are given.

  4. CAD-Based Aerodynamic Design of Complex Configurations using a Cartesian Method

    NASA Technical Reports Server (NTRS)

    Nemec, Marian; Aftosmis, Michael J.; Pulliam, Thomas H.

    2003-01-01

    A modular framework for aerodynamic optimization of complex geometries is developed. By working directly with a parametric CAD system, complex-geometry models are modified nnd tessellated in an automatic fashion. The use of a component-based Cartesian method significantly reduces the demands on the CAD system, and also provides for robust and efficient flowfield analysis. The optimization is controlled using either a genetic or quasi-Newton algorithm. Parallel efficiency of the framework is maintained even when subject to limited CAD resources by dynamically re-allocating the processors of the flow solver. Overall, the resulting framework can explore designs incorporating large shape modifications and changes in topology.

  5. Low-subsonic aerodynamic characteristics of a shuttle-orbiter configuration designed for reduced length

    NASA Technical Reports Server (NTRS)

    Ware, G. M.; Spencer, B., Jr.

    1973-01-01

    An investigation has been made in a low-turbulence pressure tunnel to determine the low-subsonic aerodynamic characteristics of a 0.01875-scale model of a potential shuttle orbiter. The design has the rocket engines mounted in fairings on either side of the body on top of the wing. The wing had a leading-edge sweep of 50 and a trailing-edge sweep of minus 4. configurations investigated included engine-mounted twin dorsal tails at various rollout angles, a body-mounted center-line vertical tail, cylindrical and boattailed afterbody, and elevon and rudder at several deflections.

  6. Simplified procedures for designing composite bolted joints

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1988-01-01

    Simplified procedures are described to design and analyze single and multi-bolt composite joints. Numerical examples illustrate the use of these methods. Factors affecting composite bolted joints are summarized. References are cited where more detailed discussion is presented on specific aspects of composite bolted joints. Design variables associated with these joints are summarized in the appendix.

  7. The aerodynamic design and performance of the NASA/GE E3 low pressure turbine

    NASA Technical Reports Server (NTRS)

    Cherry, D. G.; Dengler, R. P.

    1984-01-01

    The aerodynamic design and scaled rig test results of the low pressure turbine (LPT) component for the NASA/General Electric Energy Efficient Engine (E3) are presented. The low pressure turbine is a highly loaded five-stage design featuring high outer wall slope, controlled vortex aerodynamics, low stage flow coefficient, and reduced clearances. An assessment of its performance has been made based on a series of scaled air turbine tests which were divided into two phases: Block I (March through August, 1979) and Block II (June through September, 1981). Results from the Block II five-stage test, summarized in the paper, indicate that the E3 LPT will attain an efficiency level of 91.5 percent at the Mach 0.8/35,000 ft. max. climb altitude design point. This is relative to program goals of 91.1 percent for the E3 demonstrator engine and 91.7 percent for a fully developed flight propulsion system LPT.

  8. Optimization methods applied to the aerodynamic design of helicopter rotor blades

    NASA Technical Reports Server (NTRS)

    Walsh, Joanne L.; Bingham, Gene J.; Riley, Michael F.

    1987-01-01

    Described is a formal optimization procedure for helicopter rotor blade design which minimizes hover horsepower while assuring satisfactory forward flight performance. The approach is to couple hover and forward flight analysis programs with a general-purpose optimization procedure. The resulting optimization system provides a systematic evaluation of the rotor blade design variables and their interaction, thus reducing the time and cost of designing advanced rotor blades. The paper discusses the basis for and details of the overall procedure, describes the generation of advanced blade designs for representative Army helicopters, and compares design and design effort with those from the conventional approach which is based on parametric studies and extensive cross-plots.

  9. Rotor redesign for a highly loaded 1800 ft/sec tip speed fan. 1: Aerodynamic and mechanical design report

    NASA Technical Reports Server (NTRS)

    Norton, J. M.; Tari, U.; Weber, R. M.

    1979-01-01

    A quasi three dimensional design system and multiple-circular-arc airfoil sections were used to design a fan rotor. An axisymmetric intrablade flow field calculation modeled the shroud of an isolated splitter and radial distribution. The structural analysis indicates that the design is satisfactory for evaluation of aerodynamic performance of the fan stage in a test facility.

  10. Spatial adaptation procedures on tetrahedral meshes for unsteady aerodynamic flow calculations

    NASA Technical Reports Server (NTRS)

    Rausch, Russ D.; Batina, John T.; Yang, Henry T. Y.

    1993-01-01

    Spatial adaptation procedures for the accurate and efficient solution of steady and unsteady inviscid flow problems are described. The adaptation procedures were developed and implemented within a three-dimensional, unstructured-grid, upwind-type Euler code. These procedures involve mesh enrichment and mesh coarsening to either add points in high gradient regions of the flow or remove points where they are not needed, respectively, to produce solutions of high spatial accuracy at minimal computational cost. A detailed description of the enrichment and coarsening procedures are presented and comparisons with experimental data for an ONERA M6 wing and an exact solution for a shock-tube problem are presented to provide an assessment of the accuracy and efficiency of the capability. Steady and unsteady results, obtained using spatial adaptation procedures, are shown to be of high spatial accuracy, primarily in that discontinuities such as shock waves are captured very sharply.

  11. High Reynolds Number Hybrid Laminar Flow Control (HLFC) Flight Experiment. Report 2; Aerodynamic Design

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This document describes the aerodynamic design of an experimental hybrid laminar flow control (HLFC) wing panel intended for use on a Boeing 757 airplane to provide a facility for flight research on high Reynolds number HLFC and to demonstrate practical HLFC operation on a full-scale commercial transport airplane. The design consists of revised wing leading edge contour designed to produce a pressure distribution favorable to laminar flow, definition of suction flow requirements to laminarize the boundary layer, provisions at the inboard end of the test panel to prevent attachment-line boundary layer transition, and a Krueger leading edge flap that serves both as a high lift device and as a shield to prevent insect accretion on the leading edge when the airplane is taking off or landing.

  12. Numerical optimization - An assessment of its role in transport aircraft aerodynamic design through a case study

    NASA Technical Reports Server (NTRS)

    Lores, M. E.; Smith, P. R.; Large, R. A.

    1980-01-01

    An efficient transonic wing design procedure based upon numerical optimization together with three-dimensional transonic methods has been developed and used to design an advanced transport wing. The method development included an examination of the use of both full potential and extended small disturbance analysis codes and demonstrated that the former formulation was more reliable. In either case, the design procedure is economical and easy to use. Design verification in a unique semi-span test arrangement demonstrated that the design method produced a wing which satisfied the study design requirements. However, aeroelastic deformation of the wing occurred during the wind tunnel test. The computational methods used in the design procedure were employed to assess the effect of the aeroelastic deformation. The paper concludes with an evaluation of the design procedure and recommendation for its improvement.

  13. Aerodynamic Modeling of Transonic Aircraft Using Vortex Lattice Coupled with Transonic Small Disturbance for Conceptual Design

    NASA Technical Reports Server (NTRS)

    Chaparro, Daniel; Fujiwara, Gustavo E. C.; Ting, Eric; Nguyen, Nhan

    2016-01-01

    The need to rapidly scan large design spaces during conceptual design calls for computationally inexpensive tools such as the vortex lattice method (VLM). Although some VLM tools, such as Vorview have been extended to model fully-supersonic flow, VLM solutions are typically limited to inviscid, subcritical flow regimes. Many transport aircraft operate at transonic speeds, which limits the applicability of VLM for such applications. This paper presents a novel approach to correct three-dimensional VLM through coupling of two-dimensional transonic small disturbance (TSD) solutions along the span of an aircraft wing in order to accurately predict transonic aerodynamic loading and wave drag for transport aircraft. The approach is extended to predict flow separation and capture the attenuation of aerodynamic forces due to boundary layer viscosity by coupling the TSD solver with an integral boundary layer (IBL) model. The modeling framework is applied to the NASA General Transport Model (GTM) integrated with a novel control surface known as the Variable Camber Continuous Trailing Edge Flap (VCCTEF).

  14. An interactive version of PropID for the aerodynamic design of horizontal axis wind turbines

    SciTech Connect

    Ninham, C.P.; Selig, M.S.

    1997-12-31

    The original PROP code developed by AeroVironment, Inc. and its various versions have been in use for wind turbine performance predictions for over ten years. Due to its simplicity, rapid execution times and relatively accurate predictions, it has become an industry standard in the US. The Europeans have similar blade-element/momentum methods in use for design. Over the years, PROP has continued to be improved (in its accuracy and capability), e.g., PROPSH, PROPPC, PROP93, and PropID. The latter version incorporates a unique inverse design capability that allows the user to specify the desired aerodynamic characteristics from which the corresponding blade geometry is determined. Through this approach, tedious efforts related to manually adjusting the chord, twist, pitch and rpm to achieve desired aerodynamic/performance characteristics can be avoided, thereby making it possible to perform more extensive trade studies in an effort to optimize performance. Past versions of PropID did not have supporting graphics software. The more current version to be discussed includes a Matlab-based graphical user interface (GUI) and additional features that will be discussed in this paper.

  15. Axial compressor blade design for desensitization of aerodynamic performance and stability to tip clearance

    NASA Astrophysics Data System (ADS)

    Erler, Engin

    Tip clearance flow is the flow through the clearance between the rotor blade tip and the shroud of a turbomachine, such as compressors and turbines. This flow is driven by the pressure difference across the blade (aerodynamic loading) in the tip region and is a major source of loss in performance and aerodynamic stability in axial compressors of modern aircraft engines. An increase in tip clearance, either temporary due to differential radial expansion between the blade and the shroud during transient operation or permanent due to engine wear or manufacturing tolerances on small blades, increases tip clearance flow and results in higher fuel consumption and higher risk of engine surge. A compressor design that can reduce the sensitivity of its performance and aerodynamic stability to tip clearance increase would have a major impact on short and long-term engine performance and operating envelope. While much research has been carried out on improving nominal compressor performance, little had been done on desensitization to tip clearance increase beyond isolated observations that certain blade designs such as forward chordwise sweep, seem to be less sensitive to tip clearance size increase. The current project aims to identify through a computational study the flow features and associated mechanisms that reduces sensitivity of axial compressor rotors to tip clearance size and propose blade design strategies that can exploit these results. The methodology starts with the design of a reference conventional axial compressor rotor followed by a parametric study with variations of this reference design through modification of the camber line and of the stacking line of blade profiles along the span. It is noted that a simple desensitization method would be to reduce the aerodynamic loading of the blade tip which would reduce the tip clearance flow and its proportional contribution to performance loss. However, with the larger part of the work on the flow done in this

  16. Reliability based fatigue design and maintenance procedures

    NASA Technical Reports Server (NTRS)

    Hanagud, S.

    1977-01-01

    A stochastic model has been developed to describe a probability for fatigue process by assuming a varying hazard rate. This stochastic model can be used to obtain the desired probability of a crack of certain length at a given location after a certain number of cycles or time. Quantitative estimation of the developed model was also discussed. Application of the model to develop a procedure for reliability-based cost-effective fail-safe structural design is presented. This design procedure includes the reliability improvement due to inspection and repair. Methods of obtaining optimum inspection and maintenance schemes are treated.

  17. Comparison of Various Supersonic Turbine Tip Designs to Minimize Aerodynamic Loss and Tip Heating

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram; Ameri, Ali

    2012-01-01

    The rotor tips of axial turbines experience high heat flux and are the cause of aerodynamic losses due to tip clearance flows, and in the case of supersonic tips, shocks. As stage loadings increase, the flow in the tip gap approaches and exceeds sonic conditions. This introduces effects such as shock-boundary layer interactions and choked flow that are not observed for subsonic tip flows that have been studied extensively in literature. This work simulates the tip clearance flow for a flat tip, a diverging tip gap and several contoured tips to assess the possibility of minimizing tip heat flux while maintaining a constant massflow from the pressure side to the suction side of the rotor, through the tip clearance. The Computational Fluid Dynamics (CFD) code GlennHT was used for the simulations. Due to the strong favorable pressure gradients the simulations assumed laminar conditions in the tip gap. The nominal tip gap width to height ratio for this study is 6.0. The Reynolds number of the flow is 2.4 x 10(exp 5) based on nominal tip width and exit velocity. A wavy wall design was found to reduce heat flux by 5 percent but suffered from an additional 6 percent in aerodynamic loss coefficient. Conventional tip recesses are found to perform far worse than a flat tip due to severe shock heating. Overall, the baseline flat tip was the second best performer. A diverging converging tip gap with a hole was found to be the best choice. Average tip heat flux was reduced by 37 percent and aerodynamic losses were cut by over 6 percent.

  18. Aerodynamic design and analysis of small horizontal axis wind turbine blades

    NASA Astrophysics Data System (ADS)

    Tang, Xinzi

    This work investigates the aerodynamic design and analysis of small horizontal axis wind turbine blades via the blade element momentum (BEM) based approach and the computational fluid dynamics (CFD) based approach. From this research, it is possible to draw a series of detailed guidelines on small wind turbine blade design and analysis. The research also provides a platform for further comprehensive study using these two approaches. The wake induction corrections and stall corrections of the BEM method were examined through a case study of the NREL/NASA Phase VI wind turbine. A hybrid stall correction model was proposed to analyse wind turbine power performance. The proposed model shows improvement in power prediction for the validation case, compared with the existing stall correction models. The effects of the key rotor parameters of a small wind turbine as well as the blade chord and twist angle distributions on power performance were investigated through two typical wind turbines, i.e. a fixed-pitch variable-speed (FPVS) wind turbine and a fixed-pitch fixed-speed (FPFS) wind turbine. An engineering blade design and analysis code was developed in MATLAB to accommodate aerodynamic design and analysis of the blades.. The linearisation for radial profiles of blade chord and twist angle for the FPFS wind turbine blade design was discussed. Results show that, the proposed linearisation approach leads to reduced manufacturing cost and higher annual energy production (AEP), with minimal effects on the low wind speed performance. Comparative studies of mesh and turbulence models in 2D and 3D CFD modelling were conducted. The CFD predicted lift and drag coefficients of the airfoil S809 were compared with wind tunnel test data and the 3D CFD modelling method of the NREL/NASA Phase VI wind turbine were validated against measurements. Airfoil aerodynamic characterisation and wind turbine power performance as well as 3D flow details were studied. The detailed flow

  19. Aerodynamic control, recovery, and sensor design for a first stage flyback booster

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The mission of the flyback group is to control and recover the first stage of a commercially developed winged booster launched from a B-52 at 40,000 ft and Mach 0.8. First-stage separation occurs at 210,000 ft and Mach 8.7; the second and third stages will continue deployment of their 600 lb payload into low Earth orbit. The job of the flyback group begins at this point, employing a modified control system developed to stabilize and maneuver the separated first-stage vehicle to a suitable landing site approximately 130 miles from the launch point over the Pacific Ocean. This multidisciplinary design was accomplished by four subgroups: aerodynamic design/vehicle configuration (ADVC), trajectory optimization, controls, and thermal management.

  20. An aerodynamic design and numerical investigation of transonic centrifugal compressor stage

    NASA Astrophysics Data System (ADS)

    Yi, Weilin; Ji, Lucheng; Tian, Yong; Shao, Weiwei; Li, Weiwei; Xiao, Yunhan

    2011-09-01

    In the present paper, the design of a transonic centrifugal compressor stage with the inlet relative Mach number about 1.3 and detailed flow field investigation by three-dimensional CFD are described. Firstly the CFD program was validated by an experimental case. Then the preliminary aerodynamic design of stage completed through in-house one-dimensional code. Three types of impellers and two sets of stages were computed and analyzed. It can be found that the swept shape of leading edge has prominent influence on the performance and can enlarge the flow range. Similarly, the performance of the stage with swept impeller is better than others. The total pressure ratio and adiabatic efficiency of final geometry achieve 7:1 and 80% respectively. The vane diffuser with same airfoils along span increases attack angle at higher span, and the local flow structure and performance is deteriorated.

  1. Reaction jet and aerodynamics compound control missile autopilot design based on adaptive fuzzy sliding mode control

    NASA Astrophysics Data System (ADS)

    Wu, Zhenhui; Dong, Chaoyang

    2006-11-01

    Because of nonlinearity and strong coupling of reaction-jet and aerodynamics compound control missile, a missile autopilot design method based on adaptive fuzzy sliding mode control (AFSMC) is proposed in this paper. The universal approximation ability of adaptive fuzzy system is used to approximate the nonlinear function in missile dynamics equation during the flight of high angle of attack. And because the sliding mode control is robustness to external disturbance strongly, the sliding mode surface of the error system is constructed to overcome the influence of approximation error and external disturbance so that the actual overload can track the maneuvering command with high precision. Simulation results show that the missile autopilot designed in this paper not only can track large overload command with higher precision than traditional method, but also is robust to model uncertainty and external disturbance strongly.

  2. Aerodynamic Design of Complex Configurations Using Cartesian Methods and CAD Geometry

    NASA Technical Reports Server (NTRS)

    Nemec, Marian; Aftosmis, Michael J.; Pulliam, Thomas H.

    2003-01-01

    The objective for this paper is to present the development of an optimization capability for the Cartesian inviscid-flow analysis package of Aftosmis et al. We evaluate and characterize the following modules within the new optimization framework: (1) A component-based geometry parameterization approach using a CAD solid representation and the CAPRI interface. (2) The use of Cartesian methods in the development Optimization techniques using a genetic algorithm. The discussion and investigations focus on several real world problems of the optimization process. We examine the architectural issues associated with the deployment of a CAD-based design approach in a heterogeneous parallel computing environment that contains both CAD workstations and dedicated compute nodes. In addition, we study the influence of noise on the performance of optimization techniques, and the overall efficiency of the optimization process for aerodynamic design of complex three-dimensional configurations. of automated optimization tools. rithm and a gradient-based algorithm.

  3. The Aerodynamic Optimization of Wings at Subsonic Speeds and the Influence of Wingtip Design. Thesis

    NASA Technical Reports Server (NTRS)

    Zimmer, H.

    1987-01-01

    Some of the objectives of modern aircraft development are related to the achievement of reduced fuel consumption and aircraft noise. This investigation is mainly concerned with the aerodynamic aspects of aircraft development, i.e., reduction of induced drag. New studies of wing design, and in particular wing tips, are considered. Induced drag is important since, in cruising flight, it accounts for approximately one-third of the entire drag for the aircraft, and one-half while climbing. A survey is presented for the wing geometries and wing tip designs studied, and theoretical investigations of different planar wings with systematically varied wing tip forms are conducted. Attention is also paid to a theoretical study of some planar and nonplanar wings and their comparison with experimental data.

  4. Direct method for the design of optimal three-dimensional aerodynamic shapes

    NASA Astrophysics Data System (ADS)

    Isakova, N. P.; Kraiko, A. A.; P'yankov, K. S.

    2012-11-01

    A direct optimization method for a broad class of three-dimensional aerodynamic shapes based on the approximation of the desired geometry by Bernstein-Bézier surfaces is developed. The high efficiency of the method is demonstrated by applying it to the design of an optimal supersonic section of an axisymmetric maximum-thrust de Laval nozzle. The method is also tested as applied to the design of a three-dimensional supersonic nozzle section in a dense multi-nozzle setup. In addition to three-dimensional supersonic nozzle sections with a circular throat, nozzles with a varying throat shape are considered. The results suggest that the method can be applied to various problems of 3D shape optimization.

  5. An efficient procedure for cascade aeroelastic stability determination using nonlinear, time-marching aerodynamic solvers

    NASA Technical Reports Server (NTRS)

    Mahajan, Aparajit J.; Bakhle, Milind A.; Dowell, Earl H.

    1993-01-01

    A numerical eigenvalue problem formulation and a practical calculation procedure for exact eigenvalues and corresponding eigenvectors are developed and applied to a nonlinear, two-dimensional, time-marching full potential solver for cascade aeroelastic stability analysis. This procedure is based on the Lanczos recursive method and it directly calculates stability information about a nonlinear steady state. It is compared to conventional approaches in the frequency and time domains developed earlier and is found to be 100-10.000 times more computationally efficient. Eigenvalue constellations and the flutter results for flow through a cascade SR5 propfan airfoil are presented.

  6. Effect of design changes on aerodynamic and acoustic performance of translating-centerbody sonic inlets

    NASA Technical Reports Server (NTRS)

    Miller, B. A.

    1978-01-01

    An experimental investigation was conducted to determine the effect of design changes on the aerodynamic and acoustic performance of translating centerbody sonic inlets. Scale model inlets were tested in the Lewis Research Center's V/STOL wind tunnel. The effects of centerbody position, entry lip contraction ratio, diffuser length, and diffuser area ratio on inlet total pressure recovery, distortion, and noise suppression were investigated at static conditions and at forward velocity and angle of attack. With the centerbody in the takeoff position (retracted), good aerodynamic and acoustic performance was attained at static conditions and at forward velocity. At 0 deg incidence angle with a sound pressure level reduction of 20 dB, the total pressure recovery was 0.986. Pressure recovery at 50 deg was 0.981. With the centerbody in the approach position (extended), diffuser flow separation occurred at an incidence angle of approximately 20 deg. However, good performance was attained at lower angles. With the centerbody in the takeoff position the ability of the inlet to tolerate high incidence angles was improved by increasing the lip contraction ratio. However, at static conditions with the centerbody in the approach position, an optimum lip contraction ratio appears to exist, with both thinner and thicker lips yielding reduced performance.

  7. A comprehensive preference-based optimization framework with application to high-lift aerodynamic design

    NASA Astrophysics Data System (ADS)

    Carrese, Robert; Winarto, Hadi; Li, Xiaodong; Sóbester, András; Ebenezer, Samuel

    2012-10-01

    An integral component of transport aircraft design is the high-lift configuration, which can provide significant benefits in aircraft payload-carrying capacity. However, aerodynamic optimization of a high-lift configuration is a computationally challenging undertaking, due to the complex flow-field. The use of a designer-interactive multiobjective optimization framework is proposed, which identifies and exploits preferred regions of the Pareto frontier. Visual data mining tools are introduced to statistically extract information from the design space and confirm the relative influence of both variables and objectives to the preferred interests of the designer. The framework is assisted by the construction of time-adaptive Kriging models, which are cooperatively used with a high-fidelity Reynolds-averaged Navier-Stokes solver. The successful integration of these design tools is facilitated through the specification of a reference point, which can ideally be based on an existing design configuration. The framework is demonstrated to perform efficiently for the present case-study within the imposed computational budget.

  8. Single stage, low noise, advanced technology fan. Volume 1: Aerodynamic design

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.; Younghans, J. L.; Little, D. R.

    1976-01-01

    The aerodynamic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec 11,650 ft/sec). The fan and booster components are designed in a scale model flow size convenient for testing with existing facility and vehicle hardware. The design corrected flow per unit annulus area at the fan face is 215 kg/sec sq m (44.0 lb m/sec sq ft) with a hub-tip ratio of 0.38 at the leading edge of the fan rotor. This results in an inlet corrected airflow of 117.9 kg/sec (259.9 lb m/sec) for the selected rotor tip diameter if 90.37 cm (35.58 in.). The variable geometry inlet is designed utilizing a combination of high throat Mach number and acoustic treatment in the inlet diffuser for noise suppression (hybrid inlet). A variable fan exhaust nozzle was assumed in conjunction with the variable inlet throat area to limit the required area change of the inlet throat at approach and hence limit the overall diffusion and inlet length. The fan exit duct design was primarily influenced by acoustic requirements, including length of suppressor wall treatment; length, thickness and position on a duct splitter for additional suppressor treatment; and duct surface Mach numbers.

  9. Modification and Validation of Conceptual Design Aerodynamic Prediction Method HASC95 With VTXCHN

    NASA Technical Reports Server (NTRS)

    Albright, Alan E.; Dixon, Charles J.; Hegedus, Martin C.

    1996-01-01

    A conceptual/preliminary design level subsonic aerodynamic prediction code HASC (High Angle of Attack Stability and Control) has been improved in several areas, validated, and documented. The improved code includes improved methodologies for increased accuracy and robustness, and simplified input/output files. An engineering method called VTXCHN (Vortex Chine) for prediciting nose vortex shedding from circular and non-circular forebodies with sharp chine edges has been improved and integrated into the HASC code. This report contains a summary of modifications, description of the code, user's guide, and validation of HASC. Appendices include discussion of a new HASC utility code, listings of sample input and output files, and a discussion of the application of HASC to buffet analysis.

  10. Design and performance of a shape memory alloy-reinforced composite aerodynamic profile

    NASA Astrophysics Data System (ADS)

    Simpson, J. C.; Boller, C.

    2008-04-01

    Based on a shape memory alloy (SMA)-reinforced composite developed separately, the applicability of the composite has been demonstrated through realization of a realistically scaled aerodynamic profile of around 0.5 m span by 0.5 m root chord whose skins had been made from this composite. The design, manufacturing and assembly of the profile are described. The curved skins were manufactured with two layers of SMA wires integrated into the layup of aramid fibre prepregs. All SMA wires were connected such that they can be operated as individual sets of wires and at low voltages, similar to the conditions for electrical energy generation in a real aircraft. The profile was then mounted on a vibration test rig and excited by a shaker at its tip which allowed the dynamic performance of the profile to be validated under internal actuation conditions generated through the SMA wires.

  11. Aerodynamic heating and surface temperatures on vehicles for computer-aided design studies

    NASA Technical Reports Server (NTRS)

    Dejarnette, F. R.; Kania, L. A.; Chitty, A.

    1983-01-01

    A computer subprogram has been developed to calculate aerodynamic and radiative heating rates and to determine surface temperatures by integrating the heating rates along the trajectory of a vehicle. Convective heating rates are calculated by applying the axisymmetric analogue to inviscid surface streamlines and using relatively simple techniques to calculate laminar, transitional, or turbulent heating rates. Options are provided for the selection of gas model, transition criterion, turbulent heating method, Reynolds Analogy factor, and entropy-layer swallowing effects. Heating rates are compared to experimental data, and the time history of surface temperatures are given for a high-speed trajectory. The computer subprogram is developed for preliminary design and mission analysis where parametric studies are needed at all speeds.

  12. X based interactive computer graphics applications for aerodynamic design and education

    NASA Technical Reports Server (NTRS)

    Benson, Thomas J.; Higgs, C. Fred, III

    1995-01-01

    Six computer applications packages have been developed to solve a variety of aerodynamic problems in an interactive environment on a single workstation. The packages perform classical one dimensional analysis under the control of a graphical user interface and can be used for preliminary design or educational purposes. The programs were originally developed on a Silicon Graphics workstation and used the GL version of the FORMS library as the graphical user interface. These programs have recently been converted to the XFORMS library of X based graphics widgets and have been tested on SGI, IBM, Sun, HP and PC-Lunix computers. The paper will show results from the new VU-DUCT program as a prime example. VU-DUCT has been developed as an educational package for the study of subsonic open and closed loop wind tunnels.

  13. A comparison of two closely-related approaches to aerodynamic design optimization

    NASA Technical Reports Server (NTRS)

    Shubin, G. R.; Frank, P. D.

    1991-01-01

    Two related methods for aerodynamic design optimization are compared. The methods, called the implicit gradient approach and the variational (or optimal control) approach, both attempt to obtain gradients necessary for numerical optimization at a cost significantly less than that of the usual black-box approach that employs finite difference gradients. While the two methods are seemingly quite different, they are shown to differ (essentially) in that the order of discretizing the continuous problem, and of applying calculus, is interchanged. Under certain circumstances, the two methods turn out to be identical. We explore the relationship between these methods by applying them to a model problem for duct flow that has many features in common with transonic flow over an airfoil. We find that the gradients computed by the variational method can sometimes be sufficiently inaccurate to cause the optimization to fail.

  14. Low speed aerodynamic characteristics of a 17 percent thick airfoil section designed for general aviation applications

    NASA Technical Reports Server (NTRS)

    Mcghee, R. J.; Beasley, W. D.

    1973-01-01

    Wind-tunnel tests have been conducted to determine the low-speed two-dimensional aerodynamic characteristics of a 17-percent-thick airfoil designed for general aviation applications (GA(W)-1). The results were compared with predictions based on a theoretical method for calculating the viscous flow about the airfoil. The tests were conducted over a Mach number range from 0.10 to 0.28. Reynolds numbers based on airfoil chord varied from 2.0 million to 20.0 million. Maximum section lift coefficients greater than 2.0 were obtained and section lift-drag ratio at a lift coefficient of 1.0 (climb condition) varied from about 65 to 85 as the Reynolds number increased from about 2.0 million to 6.0 million.

  15. Aerodynamic Design of Heavy Vehicles Reporting Period January 15, 2004 through April 15, 2004

    SciTech Connect

    Leonard, A; Chatelain, P; Heineck, J; Browand, F; Mehta, R; Ortega, J; Salari, K; Storms, B; Brown, J; DeChant, L; Rubel, M; Ross, J; Hammache, M; Pointer, D; Roy, C; Hassan, B; Arcas, D; Hsu, T; Payne, J; Walker, S; Castellucci, P; McCallen, R

    2004-04-13

    Listed are summaries of the activities and accomplishments during this second-quarter reporting period for each of the consortium participants. The following are some highlights for this reporting period: (1) Experiments and computations guide conceptual designs for reduction of drag due to tractor-trailer gap flow (splitter plate), trailer underbody (wedges), and base drag (base-flap add-ons). (2) Steady and unsteady RANS simulations for the GTS geometry are being finalized for development of clear modeling guidelines with RANS. (3) Full geometry and tunnel simulations on the GCM geometry are underway. (4) CRADA with PACCAR is supporting computational parametric study to determine predictive need to include wind tunnel geometry as limits of computational domain. (5) Road and track test options are being investigated. All is ready for field testing of base-flaps at Crows Landing in California in collaboration with Partners in Advanced Transportation Highways (PATH). In addition, MAKA of Canada is providing the device and Wabash is providing a new trailer. (6) Apparatus to investigate tire splash and spray has been designed and is under construction. Michelin has offered tires with customized threads for this study. (7) Vortex methods have improved techniques for the treatment of vorticity near surfaces and spinning geometries like rotating tires. (8) Wind tunnel experiments on model rail cars demonstrate that empty coal cars exhibit substantial aerodynamic drag compared to full coal cars, indicating that significant fuel savings could be obtained by reducing the drag of empty coal cars. (9) Papers are being prepared for an exclusive conference session on the Heavy Vehicle DOE Aerodynamic Drag Project at the 34th AIAA Fluid Dynamics Conference in Portland, Oregon, June 28-July 1, 2004.

  16. Development of direct-inverse 3-D method for applied aerodynamic design and analysis

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.

    1987-01-01

    The primary tasks performed were the continued development of inverse design procedures for the TAWFIVE code, the development of corresponding relofting and trailing edge closure procedures, and the testing of the methods for a variety of cases. The period from July 1, 1986 through December 31, 1986 is covered.

  17. Quiet Clean Short-haul Experimental Engine (QCSEE). The aerodynamic and mechanical design of the QCSEE over-the-wing fan

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The aerodynamic and mechanical design of a fixed-pitch 1.36 pressure ratio fan for the over-the-wing (OTW) engine is presented. The fan has 28 blades. Aerodynamically, the fan blades were designed for a composite blade, but titanium blades were used in the experimental fan as a cost savings measure.

  18. An all-at-once reduced Hessian SQP scheme for aerodynamic design optimization

    NASA Technical Reports Server (NTRS)

    Feng, Dan; Pulliam, Thomas H.

    1995-01-01

    This paper introduces a computational scheme for solving a class of aerodynamic design problems that can be posed as nonlinear equality constrained optimizations. The scheme treats the flow and design variables as independent variables, and solves the constrained optimization problem via reduced Hessian successive quadratic programming. It updates the design and flow variables simultaneously at each iteration and allows flow variables to be infeasible before convergence. The solution of an adjoint flow equation is never needed. In addition, a range space basis is chosen so that in a certain sense the 'cross term' ignored in reduced Hessian SQP methods is minimized. Numerical results for a nozzle design using the quasi-one-dimensional Euler equations show that this scheme is computationally efficient and robust. The computational cost of a typical nozzle design is only a fraction more than that of the corresponding analysis flow calculation. Superlinear convergence is also observed, which agrees with the theoretical properties of this scheme. All optimal solutions are obtained by starting far away from the final solution.

  19. The design of missile's dome that fits both optical and aerodynamic needs

    NASA Astrophysics Data System (ADS)

    Wei, Qun; Zhang, Xin; Jia, Hongguang

    2010-10-01

    Optical guidance missiles requires a dome which fits both optical and aerodynamic needs when they attack at 3 Ma. In this study, ellipse is the figure chosen to be the dome's shape. The ellipticity ɛ is the main variable should to be decided. The optimized function was built by optical and aerodynamic performance function multiply by their weights. The optical and aerodynamic functions were all obtained by computational fluid dynamic (CFD) simulation's results after normalization. In this study, the optical and aerodynamic performances have equal weights, after optimzing the ellipticity ɛis 2 for the missile.

  20. The light airplane : modern theoretical aerodynamics as applied to light airplane design with a series of charts

    NASA Technical Reports Server (NTRS)

    Driggs, Ivan H

    1925-01-01

    T.M. 311 gave a short outline of modern theoretical aerodynamics as applied to light airplane design. This discussion may have been somewhat obscure to the nontechnical reader. A series of charts or curves should serve to clear up such obscurity as well as to more definitely emphasize those quantities most important for each flight characteristic.

  1. The DELTA MONSTER: An RPV designed to investigate the aerodynamics of a delta wing platform

    NASA Technical Reports Server (NTRS)

    Connolly, Kristen; Flynn, Mike; Gallagher, Randy; Greek, Chris; Kozlowski, Marc; Mcdonald, Brian; Mckenna, Matt; Sellar, Rich; Shearon, Andy

    1989-01-01

    The mission requirements for the performance of aerodynamic tests on a delta wind planform posed some problems, these include aerodynamic interference; structural support; data acquisition and transmission instrumentation; aircraft stability and control; and propulsion implementation. To eliminate the problems of wall interference, free stream turbulence, and the difficulty of achieving dynamic similarity between the test and actual flight aircraft that are associated with aerodynamic testing in wind tunnels, the concept of the remotely piloted vehicle which can perform a basic aerodynamic study on a delta wing was the main objective for the Green Mission - the Delta Monster. The basic aerodynamic studies were performed on a delta wing with a sweep angle greater than 45 degrees. These tests were performed at various angles of attack and Reynolds numbers. The delta wing was instrumented to determine the primary leading edge vortex formation and location, using pressure measurements and/or flow visualization. A data acquisition system was provided to collect all necessary data.

  2. Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade.

    PubMed

    Ge, Mingwei; Fang, Le; Tian, De

    2015-01-01

    At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project. PMID:26528815

  3. Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade

    PubMed Central

    Ge, Mingwei; Fang, Le; Tian, De

    2015-01-01

    At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project. PMID:26528815

  4. Monte Carlo procedure for protein design

    NASA Astrophysics Data System (ADS)

    Irbäck, Anders; Peterson, Carsten; Potthast, Frank; Sandelin, Erik

    1998-11-01

    A method for sequence optimization in protein models is presented. The approach, which has inherited its basic philosophy from recent work by Deutsch and Kurosky [Phys. Rev. Lett. 76, 323 (1996)] by maximizing conditional probabilities rather than minimizing energy functions, is based upon a different and very efficient multisequence Monte Carlo scheme. By construction, the method ensures that the designed sequences represent good folders thermodynamically. A bootstrap procedure for the sequence space search is devised making very large chains feasible. The algorithm is successfully explored on the two-dimensional HP model [K. F. Lau and K. A. Dill, Macromolecules 32, 3986 (1989)] with chain lengths N=16, 18, and 32.

  5. The engine design engine. A clustered computer platform for the aerodynamic inverse design and analysis of a full engine

    NASA Technical Reports Server (NTRS)

    Sanz, J.; Pischel, K.; Hubler, D.

    1992-01-01

    An application for parallel computation on a combined cluster of powerful workstations and supercomputers was developed. A Parallel Virtual Machine (PVM) is used as message passage language on a macro-tasking parallelization of the Aerodynamic Inverse Design and Analysis for a Full Engine computer code. The heterogeneous nature of the cluster is perfectly handled by the controlling host machine. Communication is established via Ethernet with the TCP/IP protocol over an open network. A reasonable overhead is imposed for internode communication, rendering an efficient utilization of the engaged processors. Perhaps one of the most interesting features of the system is its versatile nature, that permits the usage of the computational resources available that are experiencing less use at a given point in time.

  6. Redesigned rotor for a highly loaded, 1800 ft/sec tip speed compressor fan stage 1: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Halle, J. E.; Ruschak, J. T.

    1975-01-01

    A highly loaded, high tip-speed fan rotor was designed with multiple-circular-arc airfoil sections as a replacement for a marginally successful rotor which had precompression airfoil sections. The substitution of airfoil sections was the only aerodynamic change. Structural design of the redesigned rotor blade was guided by successful experience with the original blade. Calculated stress levels and stability parameters for the redesigned rotor are within limits demonstrated in tests of the original rotor.

  7. The aerodynamic design and performance of the General Electric/NASA EEE fan. [Energy Efficient Engine

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.; Hager, R. D.

    1983-01-01

    The aerodynamic design and test results of the fan and quarter-stage component for the GE/NASA Energy Efficient Engine (EEE) are presented. The fan is a high bypass ratio, single-stage design having 32 part-span shrouded rotor blades, coupled with a unique quarter-stage arrangement that provides additional core-stream pressure ratio and particle separation. The fan produces a bypass pressure ratio of 1.65 at the exit of the low aspect ratio vane/frame and a core-stream pressure ratio of 1.67 at the entrance to the core frame struts. The full-scale fan vehicle was instrumented, assembled and tested as a component in November 1981. Performance mapping was conducted over a range of speeds and bypass ratios using individually-controlled bypass and core-stream discharge valves. The fan bypass and core-stream test data showed excellent results, with the fan exceeding all performance goals at the important engine operating conditions.

  8. Integrating aerodynamics and structures in the minimum weight design of a supersonic transport wing

    NASA Technical Reports Server (NTRS)

    Barthelemy, Jean-Francois M.; Wrenn, Gregory A.; Dovi, Augustine R.; Coen, Peter G.; Hall, Laura E.

    1992-01-01

    An approach is presented for determining the minimum weight design of aircraft wing models which takes into consideration aerodynamics-structure coupling when calculating both zeroth order information needed for analysis and first order information needed for optimization. When performing sensitivity analysis, coupling is accounted for by using a generalized sensitivity formulation. The results presented show that the aeroelastic effects are calculated properly and noticeably reduce constraint approximation errors. However, for the particular example selected, the error introduced by ignoring aeroelastic effects are not sufficient to significantly affect the convergence of the optimization process. Trade studies are reported that consider different structural materials, internal spar layouts, and panel buckling lengths. For the formulation, model and materials used in this study, an advanced aluminum material produced the lightest design while satisfying the problem constraints. Also, shorter panel buckling lengths resulted in lower weights by permitting smaller panel thicknesses and generally, by unloading the wing skins and loading the spar caps. Finally, straight spars required slightly lower wing weights than angled spars.

  9. Design and characterization of an aerodynamic shoe sampling system for screening trace explosive materials

    NASA Astrophysics Data System (ADS)

    Staymates, Matthew; Gillen, Greg; Grandner, Jessica; Lukow, Stefan

    2011-11-01

    As part of an ongoing effort with the Transportation Security Laboratory, the National Institute of Standards and Technology has been developing a prototype shoe sampling system that relies on aerodynamic sampling as the primary mechanism for liberating, transporting, and collecting explosive contamination. This presentation will focus on the fluid dynamics associated with the current prototype design. This design includes several air jets and air blades that are used to dislodge particles from target areas of a shoe. A large blower then draws air and liberated particles into a collection device at several hundred liters per second. Experiments that utilize optical particle counting techniques have shown that the applied shear forces from these jets are capable of liberating particles efficiently from shoe surfaces. Results from real-world contamination testing also support the effectiveness of air jet impingement in this prototype. Many examples of flow visualization will be shown. The issues associated with air spillage, particle release efficiency, and particle transport will also be discussed.

  10. Aerodynamic Characteristics at High Speeds of Full-Scale Propellers having Different Shank Designs

    NASA Technical Reports Server (NTRS)

    Maynard, Julian D.

    1947-01-01

    Tests of two 10-foot-diameter two-blade propellers which differed only in shank design have been made in the Langley 16-foot high-speed tunnel. The propellers are designated by their blade design numbers, NACA 10-(5)(08)-03, which had aerodynamically efficient airfoil shank sections, and NACA l0-(5)(08)-03R which had thick cylindrical shank sections typical of conventiona1 blades, The propellers mere tested on a 2000-horsepower dynamometer through a range of blade-angles from 20deg to 55deg at various rotational speeds and at airspeeds up to 496 miles per hour. The resultant tip speeds obtained simulate actual flight conditions, and the variation of air-stream Mach number with advance ratio is within the range of full-scale constant-speed propeller operation. Both propellers were very efficient, the maximum envelope efficiency being approximately 0,95 for the NACA 10-(5)(08)-03 propeller and about 5 percent less for the NACA 10-(5)(08)-03R propeller. Based on constant power and rotational speed, the efficiency of the NACA 10-(05)(08)-03 propeller was from 2.8 to 12 percent higher than that of the NACA 10-(5)(08)-03R propeller over a range of airspeeds from 225 to 450 miles per hour. The loss in maximum efficiency at the design blade angle for the NACA 10-(5)(08)-03 and 10-(5)(08)-03R propellers vas about 22 and 25 percent, respectively, for an increase in helical tip Mach number from 0.70 to 1.14.

  11. Design and Execution of the Hypersonic Inflatable Aerodynamic Decelerator Large-Article Wind Tunnel Experiment

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.

    2013-01-01

    The testing of 3- and 6-meter diameter Hypersonic Inflatable Aerodynamic Decelerator (HIAD) test articles was completed in the National Full-Scale Aerodynamics Complex 40 ft x 80 ft Wind Tunnel test section. Both models were stacked tori, constructed as 60 degree half-angle sphere cones. The 3-meter HIAD was tested in two configurations. The first 3-meter configuration utilized an instrumented flexible aerodynamic skin covering the inflatable aeroshell surface, while the second configuration employed a flight-like flexible thermal protection system. The 6-meter HIAD was tested in two structural configurations (with and without an aft-mounted stiffening torus near the shoulder), both utilizing an instrumented aerodynamic skin.

  12. An aerodynamic analysis computer program and design notes for low speed wing flap systems

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.; Walkley, K. B.

    1983-01-01

    The expanded capabilities for analysis and design of low speed flap systems afforded by recent modifications of an existing computer program is described. The program provides for the simultaneous analysis of up to 25 pairs of leading-edge and trailing-edge flap deflection schedules. Among other new features of the program are a revised attainable thrust estimation method to provide more accurate predictions for low Mach numbers, and a choice of three options for estimation of leading-edge separation vortex flow effects. Comparison of program results with low speed experimental data for an arrow wing supersonic cruise configuration with leading-edge and trailing-edge flaps showed good agreement over most of the range of flap deflections. Other force data comparisons and an independent study of airfoil and wing pressure distributions indicated that wind-tunnel measurements of the aerodynamic performance of twisted and cambered wings and wings with leading-edge flaps can be very sensitive to Reynolds number effects.

  13. Towards Exploratory Aerodynamic Design using the Reynolds-Averaged Navier-Stokes Equations

    NASA Astrophysics Data System (ADS)

    Koo, David Tai Shun

    The aerodynamic optimization framework Jetstream is applied to problems involving lift-constrained drag minimization using the Reynolds-averaged Navier-Stokes equations. A parallel Newton-Krylov algorithm is used to solve the governing equations on multiblock structured meshes; gradients are computed using the discrete-adjoint method. Geometry parameterization and mesh movement are integrated using B-spline control volumes. Drag minimization studies from past works are revisited and strategies are devised to improve optimization convergence. These strategies include linear constraints for geometric feasibility, robust flow solver parameters, and meshing with an O-O topology. The single-point and multi-point optimization of the NASA Common Research Model (CRM) wing geometry is presented. A rectangular NACA0012 wing is optimized with planform design variables, enabling significant changes in span, sweep, taper, and airfoil section. To demonstrate Jetstream's flexibility, a wing based on the B737-900 is optimized with nonplanar winglets, split-tip, and wingtip fence configurations. Finally, the box-wing optimization in subsonic flow is revisited.

  14. Analysis of VAWT aerodynamics and design using the Actuator Cylinder flow model

    NASA Astrophysics Data System (ADS)

    Madsen, H. Aa; Paulsen, U. S.; Vitae, L.

    2014-12-01

    The actuator cylinder (AC) flow model is defined as the ideal VAWT rotor. Radial directed volume forces are applied on the circular path of the VAWT rotor airfoil and constitute an energy conversion in the flow. The power coefficient for the ideal as well as the real energy conversion is defined. The describing equations for the two-dimensional AC model are presented and a solution method splitting the final solution in a linear and non-linear part is briefly described. A family of loadforms approaching the uniform loading is used to study the ideal energy conversion indicating that the maximum power coefficient for the ideal energy conversion of a VAWT could exceed the Betz limit. The real energy conversion of the 5MW DeepWind rotor is simulated with the AC flow model in combination with the blade element analysis. Aerodynamic design aspects are discussed on this basis revealing that the maximum obtainable power coefficient for a fixed pitch VAWT is constrained by the fundamental cyclic variation of inflow angle and relative velocity leading to a loading that deviates considerably from the uniform loading.

  15. Venus In Situ Explorer Mission design using a mechanically deployed aerodynamic decelerator

    NASA Astrophysics Data System (ADS)

    Smith, B.; Venkatapathy, E.; Wercinski, P.; Yount, B.; Prabhu, D.; Gage, P.; Glaze, L.; Baker, C.

    The Venus In Situ Explorer (VISE) Mission addresses the highest priority science questions within the Venus community outlined in the National Research Council's Decadal Survey. The heritage Venus atmospheric entry system architecture, a 45° sphere-cone rigid aeroshell with a carbon phenolic thermal protection system, may no longer be the preferred entry system architecture compared to other viable alternatives being explored at NASA. A mechanically-deployed aerodynamic decelerator, known as the Adaptive Deployable Entry and Placement Technology (ADEPT), is an entry system alternative that can provide key operational benefits and risk reduction compared to a rigid aeroshell. This paper describes a mission feasibility study performed with the objectives of identifying potential adverse interactions with other mission elements and establishing requirements on decelerator performance. Feasibility is assessed through a launch-to-landing mission design study where the Venus Intrepid Tessera Lander (VITaL), a VISE science payload designed to inform the Decadal Survey results, is repackaged from a rigid aeroshell into the ADEPT decelerator. It is shown that ADEPT reduces the deceleration load on VITaL by an order of magnitude relative to a rigid aeroshell. The more benign entry environment opens up the VISE mission design environment for increased science return, reduced risk, and reduced cost. The ADEPT-VITAL mission concept of operations is presented and details of the entry vehicle structures and mechanisms are given. Finally, entry aerothermal analysis is presented that defines the operational requirements for a revolutionary structural-TPS material employed by ADEPT: three-dimensionally woven carbon cloth. Ongoing work to mitigate key risks identified in this feasibility study is presented.

  16. Development of direct-inverse 3-D methods for applied aerodynamic design and analysis

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.

    1988-01-01

    Several inverse methods have been compared and initial results indicate that differences in results are primarily due to coordinate systems and fuselage representations and not to design procedures. Further, results from a direct-inverse method that includes 3-D wing boundary layer effects, wake curvature, and wake displacement are presented. These results show that boundary layer displacements must be included in the design process for accurate results.

  17. Aerodynamic design and initial performance measurements for the SANDIA 34-metre diameter vertical-axis wind turbine

    SciTech Connect

    Berg, D.E.; Klimas, P.C.; Stephenson, W.A. )

    1989-01-01

    The DOE/Sandia 34-m diameter Vertical-Axis Wind turbine (VAWT) utilizes a step-tapered, multiple-airfoil section blade. One of the airfoil sections is a natural laminar flow profile, the SAND 0018/50, designed specifically for use on VAWTs. The turbine has now been fully operational for more than a year, and extensive turbine aerodynamic performance data have been obtained. This paper reviews the design and fabrication of the rotor blade, with emphasis on the SAND 0018/50 airfoil, and compares the performance measurements to date with the performance predictions. Possible sources of the discrepancies between measured and predicted performance are identified, and plans for additional aerodynamic testing on the turbine are briefly discussed. 12 refs., 10 figs.

  18. Aerodynamic design and initial performance measurements for the SANDIA 34-metre diameter vertical-axis wind turbine

    NASA Astrophysics Data System (ADS)

    Berg, Dale E.; Klimas, Paul C.; Stephenson, William A.

    The DOE/Sandia 34-m diameter Vertical-Axis Wind turbine (VAWT) utilizes a step-tapered, multiple-airfoil section blade. One of the airfoil sections is a natural laminar flow profile, the SAND 0018/50, designed specifically for use on VAWTs. The turbine has now been fully operational for more than a year, and extensive turbine aerodynamic performance data have been obtained. This paper reviews the design and fabrication of the rotor blade, with emphasis on the SAND 0018/50 airfoil, and compares the performance measurements to date with the performance predictions. Possible sources of the discrepancies between measured and predicted performance are identified, and plans for additional aerodynamic testing on the turbine are briefly discussed.

  19. Aerodynamic design for improved manueverability by use of three-dimensional transonic theory

    NASA Technical Reports Server (NTRS)

    Mann, M. J.; Campbell, R. L.; Ferris, J. C.

    1984-01-01

    Improvements in transonic maneuver performance by the use of three-dimensional transonic theory and a transonic design procedure were examined. The FLO-27 code of Jameson and Caughey was used to design a new wing for a fighter configuration with lower drag at transonic maneuver conditions. The wing airfoil sections were altered to reduce the upper-surface shock strength by means of a design procedure which is based on the iterative application of the FLO-27 code. The plan form of the fighter configuration was fixed and had a leading edge sweep of 45 deg and an aspect ratio of 3.28. Wind-tunnel tests were conducted on this configuration at Mach numbers from 0.60 to 0.95 and angles of attack from -2 deg to 17 deg. The transonic maneuver performance of this configuration was evaluated by comparison with a wing designed by empirical methods and a wing designed primarily by two-dimensional transonic theory. The configuration designed by the use of FLO-27 had the same or lower drag than the empirical wing and, for some conditions, lower drag than the two-dimensional design. From some maneuver conditions, the drag of the two-dimensional design was somewhat lower.

  20. Aerodynamic optimization by simultaneously updating flow variables and design parameters with application to advanced propeller designs

    NASA Technical Reports Server (NTRS)

    Rizk, Magdi H.

    1988-01-01

    A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.

  1. Systems design study of the Pioneer Venus spacecraft. Volume 1. Technical analyses and tradeoffs, section 7 (part 3 of 4). [aerodynamic design problems for small probe reentry

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The aerodynamic design problems for the Pioneer Venus mission are discussed for a small probe shape that enters the atmosphere, and exhibits good stability for the subsonic portion of the flight. The problems discussed include: heat shield, structures and mechanisms, thermal control, decelerator, probe communication, data handling and command, and electric power.

  2. A parametric study of planform and aeroelastic effects on aerodynamic center, alpha- and q- stability derivatives. Appendix D: Procedures used to determine the mass distribution for idealized low aspect ratio two spar fighter wings

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Hamler, F. R.; Reynolds, D.

    1972-01-01

    The procedures used to establish the mass matrices characteristics for the fighter type wings studied are given. A description of the procedure used to find the mass associated with a specific aerodynamic panel is presented and some examples of the application of the procedure are included.

  3. Numerical Aerodynamic Simulation

    NASA Technical Reports Server (NTRS)

    1989-01-01

    An overview of historical and current numerical aerodynamic simulation (NAS) is given. The capabilities and goals of the Numerical Aerodynamic Simulation Facility are outlined. Emphasis is given to numerical flow visualization and its applications to structural analysis of aircraft and spacecraft bodies. The uses of NAS in computational chemistry, engine design, and galactic evolution are mentioned.

  4. High-Tip-Speed, Low-Loading Transonic Fan Stage. Part 1: Aerodynamic and Mechanical Design

    NASA Technical Reports Server (NTRS)

    Wright, L. C.; Vitale, N. G.; Ware, T. C.; Erwin, J. R.

    1973-01-01

    A high-tip-speed, low-loading transonic fan stage was designed to deliver an overall pressure ratio of 1.5 with an adiabatic efficiency of 86 percent. The design flow per unit annulus area is 42.0 pounds per square foot. The fan features a hub/tip ratio of 0.46, a tip diameter of 28.74 in. and operates at a design tip speed of 1600 fps. For these design conditions, the rotor blade tip region operates with supersonic inlet and supersonic discharge relative velocities. A sophisticated quasi-three-dimensional characteristic section design procedure was used for the all-supersonic sections and the inlet of the midspan transonic sections. For regions where the relative outlet velocities are supersonic, the blade operates with weak oblique shocks only.

  5. Integrated design and manufacturing for the high speed civil transport (a combined aerodynamics/propulsion optimization study)

    NASA Technical Reports Server (NTRS)

    Baecher, Juergen; Bandte, Oliver; DeLaurentis, Dan; Lewis, Kemper; Sicilia, Jose; Soboleski, Craig

    1995-01-01

    This report documents the efforts of a Georgia Tech High Speed Civil Transport (HSCT) aerospace student design team in completing a design methodology demonstration under NASA's Advanced Design Program (ADP). Aerodynamic and propulsion analyses are integrated into the synthesis code FLOPS in order to improve its prediction accuracy. Executing the integrated product and process development (IPPD) methodology proposed at the Aerospace Systems Design Laboratory (ASDL), an improved sizing process is described followed by a combined aero-propulsion optimization, where the objective function, average yield per revenue passenger mile ($/RPM), is constrained by flight stability, noise, approach speed, and field length restrictions. Primary goals include successful demonstration of the application of the response surface methodolgy (RSM) to parameter design, introduction to higher fidelity disciplinary analysis than normally feasible at the conceptual and early preliminary level, and investigations of relationships between aerodynamic and propulsion design parameters and their effect on the objective function, $/RPM. A unique approach to aircraft synthesis is developed in which statistical methods, specifically design of experiments and the RSM, are used to more efficiently search the design space for optimum configurations. In particular, two uses of these techniques are demonstrated. First, response model equations are formed which represent complex analysis in the form of a regression polynomial. Next, a second regression equation is constructed, not for modeling purposes, but instead for the purpose of optimization at the system level. Such an optimization problem with the given tools normally would be difficult due to the need for hard connections between the various complex codes involved. The statistical methodology presents an alternative and is demonstrated via an example of aerodynamic modeling and planform optimization for a HSCT.

  6. Computational Design and Analysis of a Micro-Tab Based Aerodynamic Loads Control System for Lifting Surfaces

    SciTech Connect

    Van Dam, C P; Nakafuji, D Y; Bauer, C; Chao, D; Standish, K

    2002-11-01

    A computational design and analysis of a microtab based aerodynamic loads control system is presented. The microtab consists of a small tab that emerges from a wing approximately perpendicular to its surface in the vicinity of its trailing edge. Tab deployment on the upper side of the wing causes a decrease in the lift generation whereas deployment on the pressure side causes an increase. The computational methods applied in the development of this concept solve the governing Reynolds-averaged Navier-Stokes equations on structured, overset grids. The application of these methods to simulate the flows over lifting surface including the tabs has been paramount in the development of these devices. The numerical results demonstrate the effectiveness of the microtab and that it is possible to carry out a sensitivity analysis on the positioning and sizing of the tabs before they are implemented in successfully controlling the aerodynamic loads.

  7. Supersonic Aerodynamic Design Improvements of an Arrow-Wing HSCT Configuration Using Nonlinear Point Design Methods

    NASA Technical Reports Server (NTRS)

    Unger, Eric R.; Hager, James O.; Agrawal, Shreekant

    1999-01-01

    This paper is a discussion of the supersonic nonlinear point design optimization efforts at McDonnell Douglas Aerospace under the High-Speed Research (HSR) program. The baseline for these optimization efforts has been the M2.4-7A configuration which represents an arrow-wing technology for the High-Speed Civil Transport (HSCT). Optimization work on this configuration began in early 1994 and continued into 1996. Initial work focused on optimization of the wing camber and twist on a wing/body configuration and reductions of 3.5 drag counts (Euler) were realized. The next phase of the optimization effort included fuselage camber along with the wing and a drag reduction of 5.0 counts was achieved. Including the effects of the nacelles and diverters into the optimization problem became the next focus where a reduction of 6.6 counts (Euler W/B/N/D) was eventually realized. The final two phases of the effort included a large set of constraints designed to make the final optimized configuration more realistic and they were successful albeit with a loss of performance.

  8. Design of control laws for flutter suppression based on the aerodynamic energy concept and comparisons with other design methods

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1989-01-01

    The aerodynamic energy method is used in this paper to synthesize control laws for NASA's Drone for Aerodynamic and Structural Testing-Aerodynamic Research Wing 1 (DAST-ARW1) mathematical model. The performance of these control laws in terms of closed-loop flutter dynamic pressure, control surface activity, and robustness is compared against other control laws that appear in the literature and relate to the same model. A control law synthesis technique that makes use of the return difference singular values is developed in this paper. it is based on the aerodynamic energy approach and is shown to yield results superior to those given in the literature and based on optimal control theory. Nyquist plots are presented together with a short discussion regarding the relative merits of the minimum singular value as a measure of robustness, compared with the more traditional measure of robustness involving phase and gain margins.

  9. Design of control laws for flutter suppression based on the aerodynamic energy concept and comparisons with other design methods

    NASA Technical Reports Server (NTRS)

    Nissim, Eli

    1990-01-01

    The aerodynamic energy method is used to synthesize control laws for NASA's drone for aerodynamic and structural testing-aerodynamic research wing 1 (DAST-ARW1) mathematical model. The performance of these control laws in terms of closed-loop flutter dynamic pressure, control surface activity, and robustness is compared with other control laws that relate to the same model. A control law synthesis technique that makes use of the return difference singular values is developed. It is based on the aerodynamic energy approach and is shown to yield results that are superior to those results given in the literature and are based on optimal control theory. Nyquist plots are presented, together with a short discussion regarding the relative merits of the minimum singular value as a measure of robustness as compared with the more traditional measure involving phase and gain margins.

  10. An analytical design procedure for the determination of effective leading edge extensions on thick delta wings

    NASA Technical Reports Server (NTRS)

    Ghaffari, F.; Chaturvedi, S. K.

    1984-01-01

    An analytical design procedure for leading edge extensions (LEE) was developed for thick delta wings. This LEE device is designed to be mounted to a wing along the pseudo-stagnation stream surface associated with the attached flow design lift coefficient of greater than zero. The intended purpose of this device is to improve the aerodynamic performance of high subsonic and low supersonic aircraft at incidences above that of attached flow design lift coefficient, by using a vortex system emanating along the leading edges of the device. The low pressure associated with these vortices would act on the LEE upper surface and the forward facing area at the wing leading edges, providing an additional lift and effective leading edge thrust recovery. The first application of this technique was to a thick, round edged, twisted and cambered wing of approximately triangular planform having a sweep of 58 deg and aspect ratio of 2.30. The panel aerodynamics and vortex lattice method with suction analogy computer codes were employed to determine the pseudo-stagnation stream surface and an optimized LEE planform shape.

  11. 40 CFR 243.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 243.202-2 Section 243.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... WASTE Requirements and Recommended Procedures § 243.202-2 Recommended procedures: Design. (a)...

  12. 40 CFR 240.201-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.201-2 Section 240.201-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.201-2 Recommended procedures: Design....

  13. 40 CFR 240.203-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.203-2 Section 240.203-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.203-2 Recommended procedures: Design. (a)...

  14. 40 CFR 243.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Design. 243.202-2 Section 243.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... WASTE Requirements and Recommended Procedures § 243.202-2 Recommended procedures: Design. (a)...

  15. Three-dimensional aerodynamic design optimization using discrete sensitivity analysis and parallel computing

    NASA Astrophysics Data System (ADS)

    Oloso, Amidu Olawale

    A hybrid automatic differentiation/incremental iterative method was implemented in the general purpose advanced computational fluid dynamics code (CFL3D Version 4.1) to yield a new code (CFL3D.ADII) that is capable of computing consistently discrete first order sensitivity derivatives for complex geometries. With the exception of unsteady problems, the new code retains all the useful features and capabilities of the original CFL3D flow analysis code. The superiority of the new code over a carefully applied method of finite-differences is demonstrated. A coarse grain, scalable, distributed-memory, parallel version of CFL3D.ADII was developed based on "derivative stripmining". In this data-parallel approach, an identical copy of CFL3D.ADII is executed on each processor with different derivative input files. The effect of communication overhead on the overall parallel computational efficiency is negligible. However, the fraction of CFL3D.ADII duplicated on all processors has significant impact on the computational efficiency. To reduce the large execution time associated with the sequential 1-D line search in gradient-based aerodynamic optimization, an alternative parallel approach was developed. The execution time of the new approach was reduced effectively to that of one flow analysis, regardless of the number of function evaluations in the 1-D search. The new approach was found to yield design results that are essentially identical to those obtained from the traditional sequential approach but at much smaller execution time. The parallel CFL3D.ADII and the parallel 1-D line search are demonstrated in shape improvement studies of a realistic High Speed Civil Transport (HSCT) wing/body configuration represented by over 100 design variables and 200,000 grid points in inviscid supersonic flow on the 16 node IBM SP2 parallel computer at the Numerical Aerospace Simulation (NAS) facility, NASA Ames Research Center. In addition to making the handling of such a large

  16. Ultra high tip speed (670.6 m/sec) fan stage with composite rotor: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Halle, J. E.; Burger, G. D.; Dundas, R. E.

    1977-01-01

    A highly loaded, single-stage compressor having a tip speed of 670.6 m/sec was designed for the purpose of investigating very high tip speeds and high aerodynamic loadings to obtain high stage pressure ratios at acceptable levels of efficiency. The design pressure ratio is 2.8 at an adiabatic efficiency of 84.4%. Corrected design flow is 83.4 kg/sec; corrected design speed is 15,200 rpm; and rotor inlet tip diameter is 0.853 m. The rotor uses multiple-circular-arc airfoils from 0 to 15% span, precompression airfoils assuming single, strong oblique shocks from 21 to 43% span, and precompression airfoils assuming multiple oblique shocks from 52% span to the tip. Because of the high tip speeds, the rotor blades are designed to be fabricated of composite materials. Two composite materials were investigated: Courtaulds HTS graphite fiber in a Kerimid 601 polyimide matrix and the same fibers in a PMR polyimide matrix. In addition to providing a description of the aerodynamic and mechanical design of the 670.0 m/sec fan, discussion is presented of the results of structural tests of blades fabricated with both types of matrices.

  17. In-Trail Procedure (ITP) Algorithm Design

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.; Siminiceanu, Radu I.

    2007-01-01

    The primary objective of this document is to provide a detailed description of the In-Trail Procedure (ITP) algorithm, which is part of the Airborne Traffic Situational Awareness In-Trail Procedure (ATSA-ITP) application. To this end, the document presents a high level description of the ITP Algorithm and a prototype implementation of this algorithm in the programming language C.

  18. DESIGN PROCEDURES FOR DISSOLVED OXYGEN CONTROL OF ACTIVATED SLUDGE PROCESSES

    EPA Science Inventory

    This report presents design procedures and guidelines for the selection of aeration equipment and dissolved (DO) control systems for activated sludge treatment plants. Aeration methods, equipment and application techniques are examined and selection procedures offered. Various DO...

  19. Designing Integrated Fuzzy Guidance Law for Aerodynamic Homing Missiles Using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Omar, Hanafy M.

    The Fuzzy logic controller (FLC) is well-known for robustness to parameter variations and ability to reject noise. However, its design requires definition of many parameters. This work proposes a systematic and simple procedure to develop an integrated fuzzy-based guidance law which consists of three FLC. Each is activated in a region of the interception. Another fuzzy-based switching system is introduced to allow smooth transition between these controllers. The parameters of all the fuzzy controllers, which include the distribution of the membership functions and the rules, are obtained simply by observing the function of each controller. Furthermore, these parameters are tuned by genetic algorithms by solving an optimization problem to minimize the interception time, missile acceleration commands, and miss distance. The simulation results show that the proposed procedure can generate a guidance law with satisfactory performance.

  20. Development of multidisciplinary design optimization procedures for smart composite wings and turbomachinery blades

    NASA Astrophysics Data System (ADS)

    Jha, Ratneshwar

    Multidisciplinary design optimization (MDO) procedures have been developed for smart composite wings and turbomachinery blades. The analysis and optimization methods used are computationally efficient and sufficiently rigorous. Therefore, the developed MDO procedures are well suited for actual design applications. The optimization procedure for the conceptual design of composite aircraft wings with surface bonded piezoelectric actuators involves the coupling of structural mechanics, aeroelasticity, aerodynamics and controls. The load carrying member of the wing is represented as a single-celled composite box beam. Each wall of the box beam is analyzed as a composite laminate using a refined higher-order displacement field to account for the variations in transverse shear stresses through the thickness. Therefore, the model is applicable for the analysis of composite wings of arbitrary thickness. Detailed structural modeling issues associated with piezoelectric actuation of composite structures are considered. The governing equations of motion are solved using the finite element method to analyze practical wing geometries. Three-dimensional aerodynamic computations are performed using a panel code based on the constant-pressure lifting surface method to obtain steady and unsteady forces. The Laplace domain method of aeroelastic analysis produces root-loci of the system which gives an insight into the physical phenomena leading to flutter/divergence and can be efficiently integrated within an optimization procedure. The significance of the refined higher-order displacement field on the aeroelastic stability of composite wings has been established. The effect of composite ply orientations on flutter and divergence speeds has been studied. The Kreisselmeier-Steinhauser (K-S) function approach is used to efficiently integrate the objective functions and constraints into a single envelope function. The resulting unconstrained optimization problem is solved using the

  1. Off-design computer code for calculating the aerodynamic performance of axial-flow fans and compressors

    NASA Technical Reports Server (NTRS)

    Schmidt, James F.

    1995-01-01

    An off-design axial-flow compressor code is presented and is available from COSMIC for predicting the aerodynamic performance maps of fans and compressors. Steady axisymmetric flow is assumed and the aerodynamic solution reduces to solving the two-dimensional flow field in the meridional plane. A streamline curvature method is used for calculating this flow-field outside the blade rows. This code allows for bleed flows and the first five stators can be reset for each rotational speed, capabilities which are necessary for large multistage compressors. The accuracy of the off-design performance predictions depend upon the validity of the flow loss and deviation correlation models. These empirical correlations for the flow loss and deviation are used to model the real flow effects and the off-design code will compute through small reverse flow regions. The input to this off-design code is fully described and a user's example case for a two-stage fan is included with complete input and output data sets. Also, a comparison of the off-design code predictions with experimental data is included which generally shows good agreement.

  2. A Design Procedure for the Applications-Specific Electric Motors

    NASA Astrophysics Data System (ADS)

    Hoshino, Akihiro; Isobe, Shin-Ichi; Morimoto, Masayuki; Kosaka, Takashi; Matsui, Nobuyuki

    A design procedure for the Applications-Specific Electric Motors (ASEM) is proposed. The proposed design procedure is relevant to the design of the permanent magnet synchronous motor which fulfills required typical operating points under the restrictions of dimensions and the power source conditions. The design procedure is composed of two stages, a rough design and an accurate design. A rough design finds a permissible area of the combination of motor constants which satisfy the given typical operating points under the given power source conditions. According to the obtained permissible area of motor constants, an accurate design achieves the detailed motor design determining the dimensions, the winding specifications and constituent materials. Among several designed motors, one with highest fitness from standpoints of high efficiency, manufacturability and cost is finally selected. The experimental studies show that the designed motor using the proposed procedure satisfies the requirements in the target application.

  3. 40 CFR 240.206-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.206-2 Section 240.206-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.206-2 Recommended procedures: Design. Thermal processing facilities should be designed for ease...

  4. 40 CFR 240.207-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.207-2 Section 240.207-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.207-2 Recommended procedures: Design. The facility should be designed so that it is...

  5. 40 CFR 240.208-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.208-2 Section 240.208-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.208-2 Recommended procedures: Design. Thermal processing facilities should be so designed as...

  6. Aerodynamic Design of Axial-flow Compressors. VI - Experimental Flow in Two-Dimensional Cascades

    NASA Technical Reports Server (NTRS)

    Lieblein, Seymour

    1955-01-01

    Available experimental two-dimensional cascade data for conventional compressor blade sections are correlated at a reference incidence angle in the region of minimum loss. Variations of reference incidence angle, total-pressure loss, and deviation angle with cascade geometry, inlet Mach number, and Reynolds number are investigated. From the analysis and the correlations of the available data, rules and relations are evolved for the prediction of blade-profile performance. These relations are developed in simplified forms readily applicable to compressor design procedures.

  7. Details of insect wing design and deformation enhance aerodynamic function and flight efficiency.

    PubMed

    Young, John; Walker, Simon M; Bomphrey, Richard J; Taylor, Graham K; Thomas, Adrian L R

    2009-09-18

    Insect wings are complex structures that deform dramatically in flight. We analyzed the aerodynamic consequences of wing deformation in locusts using a three-dimensional computational fluid dynamics simulation based on detailed wing kinematics. We validated the simulation against smoke visualizations and digital particle image velocimetry on real locusts. We then used the validated model to explore the effects of wing topography and deformation, first by removing camber while keeping the same time-varying twist distribution, and second by removing camber and spanwise twist. The full-fidelity model achieved greater power economy than the uncambered model, which performed better than the untwisted model, showing that the details of insect wing topography and deformation are important aerodynamically. Such details are likely to be important in engineering applications of flapping flight. PMID:19762645

  8. Aerodynamic design applying automatic differentiation and using robust variable fidelity optimization

    NASA Astrophysics Data System (ADS)

    Takemiya, Tetsushi

    , and that (2) the AMF terminates optimization erroneously when the optimization problems have constraints. The first problem is due to inaccuracy in computing derivatives in the AMF, and the second problem is due to erroneous treatment of the trust region ratio, which sets the size of the domain for an optimization in the AMF. In order to solve the first problem of the AMF, automatic differentiation (AD) technique, which reads the codes of analysis models and automatically generates new derivative codes based on some mathematical rules, is applied. If derivatives are computed with the generated derivative code, they are analytical, and the required computational time is independent of the number of design variables, which is very advantageous for realistic aerospace engineering problems. However, if analysis models implement iterative computations such as computational fluid dynamics (CFD), which solves system partial differential equations iteratively, computing derivatives through the AD requires a massive memory size. The author solved this deficiency by modifying the AD approach and developing a more efficient implementation with CFD, and successfully applied the AD to general CFD software. In order to solve the second problem of the AMF, the governing equation of the trust region ratio, which is very strict against the violation of constraints, is modified so that it can accept the violation of constraints within some tolerance. By accepting violations of constraints during the optimization process, the AMF can continue optimization without terminating immaturely and eventually find the true optimum design point. With these modifications, the AMF is referred to as "Robust AMF," and it is applied to airfoil and wing aerodynamic design problems using Euler CFD software. The former problem has 21 design variables, and the latter 64. In both problems, derivatives computed with the proposed AD method are first compared with those computed with the finite

  9. A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles

    SciTech Connect

    2001-09-01

    The project tasks and deliverables are as follows: Computations and Experiments--(1) Simulation and analysis of a range of generic shapes, simplified to more complex, representative of tractor and integrated tractor-trailer flow characteristics using computational tools, (2) The establishment of an experimental data base for tractor-trailer models for code/computational method development and validation. The first shapes to be considered will be directed towards the investigation of tractor-trailer gaps and mismatch of tractor-trailer heights. (3) The evaluation and documentation of effective computational approaches for application to heavy vehicle aerodynamics based on the benchmark results with existing and advanced computational tools compared to experimental data, and (4) Computational tools and experimental methods for use by industry, National Laboratories, and universities for the aerodynamic modeling of heavy truck vehicles. Evaluation of current and new technologies--(1) The evaluation and documentation of current and new technologies for drag reduction based on published literature and continued communication with the heavy vehicle industry (e.g., identification and prioritization of tractor-trailer drag-sources, blowing and/or suction devices, body shaping, new experimental methods or facilities), and the identification and analysis of tractor and integrated tractor-trailer aerodynamic problem areas and possible solution strategies. (2) Continued industrial site visits. It should be noted that ''CFD tools'' are not only the actual computer codes, but descriptions of appropriate numerical solution methods. Part of the project effort will be to determine the restrictions or avenues for technology transfer.

  10. Aerodynamic performances of three fan stator designs operating with rotor having tip speed of 337 meters per second and pressure ratio of 1.54. 1: Experimental performance

    NASA Technical Reports Server (NTRS)

    Gelder, T. F.

    1980-01-01

    The aerodynamic performances of four stator-blade rows are presented and evaluated. The aerodynamic designs of two of these stators were compromised to reduce noise, a third design was not. On a calculated operating line passing through the design point pressure ratio, the best stator had overall pressure-ratio and efficiency decrements of 0.031 and 0.044, respectively, providing a stage pressure ratio of 1.483 and efficiency of 0.865. The other stators showed some correctable deficiencies due partly to the design compromises for noise. In the end-wall regions blade-element losses were significantly less for the shortest chord studied.

  11. Numerical investigation of the aerodynamic performance for the newly designed cavity vane type vertical axis wind turbine

    NASA Astrophysics Data System (ADS)

    Suffer, K. H.; Usubamatov, R.; Quadir, G. A.; Ismail, K. A.

    2015-05-01

    Research and development activities in the field of renewable energy, especially wind and solar, have been considerably increased, due to the worldwide energy crisis and high global emission. However, the available technical designs are not yet adequate to develop a reliable distributed wind energy converter for low wind speed conditions. The last few years have proved that Vertical Axis Wind Turbines (VAWTs) are more suitable for urban areas than Horizontal Axis Wind Turbines (HAWTs). To date, very little has been published in this area to assess good performance and lifetime of VAWTs either in open or urban areas. The power generated by vertical axis wind turbines is strongly dependent on the aerodynamic performance of the turbines. The main goal of this current research is to investigate numerically the aerodynamic performance of a newly designed cavity type vertical axis wind turbine. In the current new design the power generated depends on the drag force generated by the individual blades and interactions between them in a rotating configuration. For numerical investigation, commercially available computational fluid dynamic (CFD) software GAMBIT and FLUENT were used. In this numerical analysis the Shear Stress Transport (SST) k-ω turbulence model is used which is better than the other turbulence models available as suggested by some researchers. The computed results show good agreement with published experimental results.

  12. The development and application of aerodynamic uncertainties in the design of the entry trajectory and flight control system of the Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Gamble, J. D.; Young, J. C.

    1982-01-01

    In connection with the decision to conduct with the Shuttle an orbital, manned mission on its first launch, certain problems arose related to mission safety, which had to be provided without the benefit of either a graduated flight test program or an initial unmanned flight concept. In an attempt to overcome these problems, the philosophy was adopted to provide a reasonable estimate of maximum possible errors in the preflight predicted aerodynamics. The flight control system (FCS) was to be certified on the basis of the estimated errors prior to STS-1. A set of 'worst case' aerodynamic uncertainties, defined as variations, was developed. As part of the first flight certification, variations, combined with other system uncertainties, were used to 'stress' the FCS through a multitude of simulations. Attention is given to an Orbiter description, the entry mission, the correlation of aerodynamic uncertainties, the application of aerodynamic variation in FCS and trajectory design, and the flight test results.

  13. Missile aerodynamics

    NASA Technical Reports Server (NTRS)

    Nielsen, Jack N.

    1988-01-01

    The fundamental aerodynamics of slender bodies is examined in the reprint edition of an introductory textbook originally published in 1960. Chapters are devoted to the formulas commonly used in missile aerodynamics; slender-body theory at supersonic and subsonic speeds; vortices in viscid and inviscid flow; wing-body interference; downwash, sidewash, and the wake; wing-tail interference; aerodynamic controls; pressure foredrag, base drag, and skin friction; and stability derivatives. Diagrams, graphs, tables of terms and formulas are provided.

  14. Simplified design procedures for fiber composite structural components/joints

    NASA Technical Reports Server (NTRS)

    Murthy, P. L. N.; Chamis, Christos C.

    1990-01-01

    Simplified step-by-step design procedures are summarized, which are suitable for the preliminary design of composite structural components such as panels (laminates) and composite built-up structures (box beams). Similar procedures are also summarized for the preliminary design of composite bolted and adhesively bonded joints. The summary is presented in terms of sample design cases complemented with typical results. Guidelines are provided which can be used in the design selection process of composite structural components/joints. Also, procedures to account for cyclic loads, hygrothermal effects and lamination residual stresses are included.

  15. Statistical design of mass spectrometry calibration procedures

    SciTech Connect

    Bayne, C.K.

    1996-11-01

    The main objective of this task was to agree on calibration procedures to estimate the system parameters (i.e., dead-time correction, ion-counting conversion efficiency, and detector efficiency factors) for SAL`s new Finnigan MAT-262 mass spectrometer. SAL will use this mass spectrometer in a clean-laboratory which was opened in December 1995 to measure uranium and plutonium isotopes on environmental samples. The Finnigan MAT-262 mass spectrometer has a multi-detector system with seven Faraday cup detectors and one ion- counter for the measurement of very small signals (e.g. 10{sup -17} Ampere range). ORNL has made preliminary estimates of the system parameters based on SAL`s experimental data measured in late 1994 when the Finnigan instrument was relatively new. SAL generated additional data in 1995 to verify the calibration procedures for estimating the dead-time correction factor, the ion-counting conversion factor and the Faraday cup detector efficiency factors. The system parameters estimated on the present data will have to be reestablished when the Finnigan MAT-262 is moved-to the new clean- laboratory. Different methods will be used to analyzed environmental samples than the current measurement methods being used. For example, the environmental samples will be electroplated on a single filament rather than using the current two filament system. An outline of the calibration standard operating procedure (SOP) is included.

  16. 40 CFR 240.210-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.210-2 Section 240.210-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.210-2 Recommended procedures: Design. Not applicable....

  17. 40 CFR 240.211-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.211-2 Section 240.211-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.211-2 Recommended procedures: Design. Continuously recording instrumentation should be used...

  18. 40 CFR 240.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.202-2 Section 240.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.202-2 Recommended procedures: Design. (a) Whenever possible, thermal processing facilities...

  19. 40 CFR 240.205-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.205-2 Section 240.205-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.205-2 Recommended procedures: Design. (a) These requirements should be met by using...

  20. 40 CFR 240.209-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.209-2 Section 240.209-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.209-2 Recommended procedures: Design. (a) Attention should be given to the safety of operators...

  1. 40 CFR 240.204-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 240.204-2 Section 240.204-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... § 240.204-2 Recommended procedures: Design. (a) Effluent waters should not be...

  2. Simple procedure for schematic design of passive solar buildings

    SciTech Connect

    Wray, W.O.; Kosiewicz, C.E.

    1984-01-01

    A simple procedure for use during the schematic phase of passive solar building design is presented in this article. The procedure is quantitative and accurate enough to insure that designs based on the provided starting point values of the primary building parameters will be cost effective.

  3. Aerodynamic design of a Coanda induced force and thruster anti-torque system

    NASA Technical Reports Server (NTRS)

    Velkoff, Henry R.; Tung, Chee

    1991-01-01

    A general method of analysis of the external and internal aerodynamics of a generic Coanda induced circulation anti-torque system is presented. The technique gives moment about the yaw axis and download induced on the boom as well as the force developed by an aft jet. The external flows including downwash, wake swirl and the boom circulation are considered. The internal flow and losses through the duct, fan, blown slots, cascades and nozzle are considered on a step-by-step basis. Limited comparison is made with open data where available.

  4. Aerodynamic Shutoff Valve

    NASA Technical Reports Server (NTRS)

    Horstman, Raymond H.

    1992-01-01

    Aerodynamic flow achieved by adding fixed fairings to butterfly valve. When valve fully open, fairings align with butterfly and reduce wake. Butterfly free to turn, so valve can be closed, while fairings remain fixed. Design reduces turbulence in flow of air in internal suction system. Valve aids in development of improved porous-surface boundary-layer control system to reduce aerodynamic drag. Applications primarily aerospace. System adapted to boundary-layer control on high-speed land vehicles.

  5. Assessment of two fast codes used for preliminary aerodynamic design of guided projectiles

    NASA Astrophysics Data System (ADS)

    Mikhail, Ameer G.

    1986-07-01

    Two missile aerodynamic prediction fast codes, namely NSWCAP and Missile-DATCOM, have been applied to the geometry of the guided, gun-launched Copperhead projectile. Assessment of the two codes was made in comparison with wind tunnel and free-flight range test data. Two configurations were considered for computation: the launch configuration (body-tail) in the Mach range of 0.5 to 1.8 and the maneuvering configuration (body-wing-tail) in the Mach range of 0.3 to 0.95. Results show reasonable agreement for the drag coefficient, C sub D, and show very large disagreements for both C sub N sub alpha and C sub M sub alpha. The incapability of both codes to include body slots and fin gap effects seems to have contributed largely to these differences. The dynamic derivatives C sub l sub p and (C sub M sub q + C sub M sub alpha) are not adequately estimated by the NSWCAP code, and are not calculated in the DATCOM code. For the coefficients actually computed, the DATCOM code results were slightly more accurate than those of the NSWCAP code. Both codes lack the determination of the explicit effects of control surface deflection angles on the aerodynamic coefficients. Development is needed for the determination if both codes are to be used for predictions for guided projectiles. Several areas of improvements in both codes are identified.

  6. Lobed Mixer Design for Noise Suppression: Plume, Aerodynamic and Acoustic Data. Volume 2

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Baker, V. David; Dalton, William N.; Bridges, James (Technical Monitor)

    2002-01-01

    A comprehensive database for the acoustic and aerodynamic characteristics of several model-scale lobe mixers of bypass ratio 5 to 6 has been created for mixed jet speeds up to 1080 ft per s at typical take-off (TO) conditions of small-to-medium turbofan engines. The flight effect was simulated for Mach numbers up to 0.3. The static thrust performance and plume data were also obtained at typical TO and cruise conditions. The tests were done at NASA Lewis anechoic dome and ASE's FluiDyne Laboratories. The effect of several lobe mixer and nozzle parameters, such as, lobe scalloping, lobe count, lobe penetration and nozzle length was examined in terms of flyover noise at constant altitude and also noise in the reference frame of the nozzle. This volume is divided into three parts: in the first two parts, we collate the plume survey data in graphical form (line, contour and surface plots) and analyze it; in part 3, we tabulate the aerodynamic data for the acoustics tests and the acoustic data in one-third octave band levels.

  7. Low-speed aerodynamic characteristics of a 13 percent thick medium speed airfoil designed for general aviation applications

    NASA Technical Reports Server (NTRS)

    Mcghee, R. J.; Beasley, W. D.

    1979-01-01

    Wind tunnel tests were conducted to determine the low speed, two dimensional aerodynamic characteristics of a 13percent thick medium speed airfoil designed for general aviation applications. The results were compared with data for the 13 percent thick low speed airfoil. The tests were conducted over a Mach number range from 0.10 to 0.32, a chord Reynolds number range from 2.0 x 10 to the 6th power to 12.0 x 10 to the 6th power, and an angle of attack frange from about -8 deg to 10 deg. The objective of retaining good high-lift low speed characteristics for an airfoil designed to have good medium speed cruise performance was achieved.

  8. The design, analysis, and testing of a low-budget wind-tunnel flutter model with active aerodynamic controls

    NASA Technical Reports Server (NTRS)

    Bolding, R. M.; Stearman, R. O.

    1976-01-01

    A low budget flutter model incorporating active aerodynamic controls for flutter suppression studies was designed as both an educational and research tool to study the interfering lifting surface flutter phenomenon in the form of a swept wing-tail configuration. A flutter suppression mechanism was demonstrated on a simple semirigid three-degree-of-freedom flutter model of this configuration employing an active stabilator control, and was then verified analytically using a doublet lattice lifting surface code and the model's measured mass, mode shapes, and frequencies in a flutter analysis. Preliminary studies were significantly encouraging to extend the analysis to the larger degree of freedom AFFDL wing-tail flutter model where additional analytical flutter suppression studies indicated significant gains in flutter margins could be achieved. The analytical and experimental design of a flutter suppression system for the AFFDL model is presented along with the results of a preliminary passive flutter test.

  9. Aerodynamic airfoil design using the Euler equations based on the dynamic evolution method and the control theory

    NASA Astrophysics Data System (ADS)

    Gao, YingYing; He, Feng; Shen, MengYu

    2011-04-01

    Based on the idea of adjoint method and the dynamic evolution method, a new optimum aerodynamic design technique is presented in this paper. It can be applied to the optimum problems with a large number of design variables and is time saving. The key of the new method lies in that the optimization process is regarded as an unsteady evolution, i.e., the optimization is executed, simultaneously with solving the unsteady flow governing equations and adjoint equations. Numerical examples for both the inverse problem and drag minimization using Euler equations have been presented, and the results show that the method presented in this paper is more efficient than the optimum methods based on the steady flow solution and the steady solution of adjoint equations.

  10. Longitudinal aerodynamic characteristics of a generic fighter model with a wing designed for sustained transonic maneuver conditions

    NASA Technical Reports Server (NTRS)

    Ferris, J. C.

    1986-01-01

    A wind-tunnel investigation was made to determine the longitudinal aerodynamic characteristics of a fixed-wing generic fighter model with a wing designed for sustained transonic maneuver conditions. The airfoil sections on the wing were designed with a two-dimensional nonlinear computer code, and the root and tip section were modified with a three-dimensional code. The wing geometric characteristics were as follows: a leading-edge sweep of 45 degrees, a taper ratio of 0.2141, an aspect ratio of 3.30, and a thickness ratio of 0.044. The model was investigated at Mach numbers from 0.600 to 1.200, at Reynolds numbers, based on the model reference length, from 2,560,000 to 3,970,000, and through a model angle-of-attack range from -5 to +18 degrees.

  11. Automated Procedure for Roll Pass Design

    NASA Astrophysics Data System (ADS)

    Lambiase, F.; Langella, A.

    2009-04-01

    The aim of this work has been to develop an automatic roll pass design method, capable of minimizing the number of roll passes. The adoption of artificial intelligence technologies, particularly expert systems, and a hybrid model for the surface profile evaluation of rolled bars, has allowed us to model the search for the minimal sequence with a tree path search. This approach permitted a geometrical optimization of roll passes while allowing automation of the roll pass design process. Moreover, the heuristic nature of the inferential engine contributes a great deal toward reducing search time, thus allowing such a system to be employed for industrial purposes. Finally, this new approach was compared with other recently developed automatic systems to validate and measure possible improvements among them.

  12. Asymmetric aerodynamic forces on aircraft at high angles of attack - some design guides

    NASA Technical Reports Server (NTRS)

    Chapman, G. T.; Keener, E. R.; Malcolm, G. N.

    1976-01-01

    Aerodynamic side forces on forebodies are considered that are produced by two types of flow: asymmetric vortices on bodies of revolution and nonuniform flow separation on square bodies with rounded corners under spinning conditions. Steady side forces that can be as large as the normal force are produced by asymmetric vortices on pointed forebodies. This side force has a large variation with Reynolds number, decreases rapidly with Mach number, and can be nearly eliminated with small nose bluntness or strakes. The angle of attack where the side force first occurs depends primarily on body geometry. The theoretical techniques to predict these side forces are necessarily semi-empirical because the basic phenomenon is not well understood. The side forces produced by nonuniform flow separation under spinning conditions depend extensively on spin rate, angle of attack, and Reynolds number. The application of simple crossflow theory to predict this side force is inadequate much below angles of attack of 90 deg.

  13. Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.

    PubMed

    Zhang, G Q; Yu, S C M

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the "ventilation" in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  14. Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle

    PubMed Central

    Zhang, G. Q.; Yu, S. C. M.

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  15. JSC Design and Procedural Standards, JSC-STD-8080

    NASA Technical Reports Server (NTRS)

    Punch, Danny T.

    2011-01-01

    This document provides design and procedural requirements appropriate for inclusion in specifications for any human spaceflight program, project, spacecraft, system, or end item. The term "spacecraft" as used in the standards includes launch vehicles, orbital vehicles, non-terrestrial surface vehicles, and modules. The standards are developed and maintained as directed by Johnson Space Center (JSC) Policy Directive JPD 8080.2, JSC Design and Procedural Standards for Human Space Flight Equipment. The Design and Procedural Standards contained in this manual represent human spacecraft design and operational knowledge applicable to a wide range of spaceflight activities. These standards are imposed on JSC human spaceflight equipment through JPD 8080.2. Designers shall comply with all design standards applicable to their design effort.

  16. The design of fibre-reinforced composite blades for passive and active wind turbine rotor aerodynamic control

    NASA Astrophysics Data System (ADS)

    Karaolis, Nicos M.

    An alternative method of varying the pitch of wind turbine rotor blades is examined, which relies on the use of fiber reinforced composite materials to design the blades so as to develop elastic coupling between an applied load of a generally twisting and non-twisting nature. With such an approach, twist can be obtained either by using one of the forces experienced by the blade during operation to alter passively the blade pitch, or by internal pressurization to control actively the blade pitch by varying the pressure. The passive control option is considered in detail. First the relevant composite construction geometries that produce the desired coupling effect are identified and then a theoretical model is developed. This is also used to explore the variation in coupling and stiffness properties with the fiber orientation. Various materials are considered including glass, aramid, and carbon fiber epoxy composites. Subsequently, the structural model is confirmed experimentally by a series of tests on composite, foam-cored beams specially designed and manufactured for this purpose. It is then combined with existing aerodynamic theories in order to model the performance of horizontal and vertical axis rotors employing such blades. The effect of passively induced twist on the aerodynamic performance is examined both theoretically and experimentally. Additionally, a simplified dynamic model is developed to obtain a general idea on how built-in elastic coupling may affect the dynamic stability of a horizontal axis rotor system. The active control option is considered in general as an alternative mechanism of inducing twist. The relevant theory is derived and illustrated with examples, and the realistic practicability of this concept is discussed. To validate the theory, a composite cylindrical shell has been designed, manufactured and tested under pressure.

  17. 40 CFR 243.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Recommended procedures: Design. 243.202-2 Section 243.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE STORAGE AND COLLECTION OF RESIDENTIAL, COMMERCIAL, AND INSTITUTIONAL SOLID WASTE Requirements and Recommended Procedures...

  18. 40 CFR 243.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Recommended procedures: Design. 243.202-2 Section 243.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE STORAGE AND COLLECTION OF RESIDENTIAL, COMMERCIAL, AND INSTITUTIONAL SOLID WASTE Requirements and Recommended Procedures §...

  19. 40 CFR 243.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommended procedures: Design. 243.200-2 Section 243.200-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE STORAGE AND COLLECTION OF RESIDENTIAL, COMMERCIAL, AND INSTITUTIONAL SOLID WASTE Requirements and Recommended Procedures §...

  20. 40 CFR 243.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WASTE Requirements and Recommended Procedures § 243.200-2 Recommended procedures: Design. (a) Reusable waste containers should be constructed of corrosion resistant metal or other material which will not... containers and which is maintained in a clean, spillage-free condition. (1) Reusable waste containers...

  1. 40 CFR 243.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WASTE Requirements and Recommended Procedures § 243.200-2 Recommended procedures: Design. (a) Reusable waste containers should be constructed of corrosion resistant metal or other material which will not... containers and which is maintained in a clean, spillage-free condition. (1) Reusable waste containers...

  2. 40 CFR 243.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WASTE Requirements and Recommended Procedures § 243.200-2 Recommended procedures: Design. (a) Reusable waste containers should be constructed of corrosion resistant metal or other material which will not... containers and which is maintained in a clean, spillage-free condition. (1) Reusable waste containers...

  3. SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems, due to the complex nature of the problems, the need for complex assessments, and complicated ...

  4. Low-speed aerodynamic characteristics of a 17-percent-thick medium speed airfoil designed for general aviation applications

    NASA Technical Reports Server (NTRS)

    Mcghee, R. J.; Beaseley, W. D.

    1980-01-01

    Wind tunnel tests were conducted to determine the low speed two dimensional aerodynamic characteristics of a 17 percent thick medium speed airfoil (MS(1)-0317) designed for general aviation applications. The results were compared with data for the 17 percent thick low speed airfoil (LS(1)-0417) and the 13 percent thick medium speed airfoil (MS(1)-0313). Theoretical predictions of the drag rise characteristics of this airfoil are also provided. The tests were conducted in the Langley low turbulence pressure tunnel over a Mach number range from 0.10 to 0.32, a chord Reynolds number range from 2 million to 12 million, and an angle of attack range from about -8 to 20 deg.

  5. Applied computational aerodynamics

    SciTech Connect

    Henne, P.A.

    1990-01-01

    The present volume discusses the original development of the panel method, the mapping solutions and singularity distributions of linear potential schemes, the capabilities of full-potential, Euler, and Navier-Stokes schemes, the use of the grid-generation methodology in applied aerodynamics, subsonic airfoil design, inverse airfoil design for transonic applications, the divergent trailing-edge airfoil innovation in CFD, Euler and potential computational results for selected aerodynamic configurations, and the application of CFD to wing high-lift systems. Also discussed are high-lift wing modifications for an advanced-capability EA-6B aircraft, Navier-Stokes methods for internal and integrated propulsion system flow predictions, the use of zonal techniques for analysis of rotor-stator interaction, CFD applications to complex configurations, CFD applications in component aerodynamic design of the V-22, Navier-Stokes computations of a complete F-16, CFD at supersonic/hypersonic speeds, and future CFD developments.

  6. Lobed Mixer Design for Noise Suppression Acoustic and Aerodynamic Test Data Analysis

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Dalton, William N.; Boyd, Kathleen (Technical Monitor); Bridges, James (Technical Monitor)

    2002-01-01

    A comprehensive database for the acoustic and aerodynamic characteristics of several model-scale lobe mixers of bypass ratio 5 to 6 has been created for mixed jet speeds up to 1080 ft/s at typical take-off (TO) conditions of small-to-medium turbofan engines. The flight effect was simulated for Mach numbers up to 0.3. The static thrust performance and plume data were also obtained at typical TO and cruise conditions. The tests were done at NASA Lewis anechoic dome and ASK's FluiDyne Laboratories. The effect of several lobe mixer and nozzle parameters, such as, lobe scalloping, lobe count, lobe penetration and nozzle length was examined in terms of flyover noise at constant altitude. Sound in the nozzle reference frame was analyzed to understand the source characteristics. Several new concepts, mechanisms and methods are reported for such lobed mixers, such as, "boomerang" scallops, "tongue" mixer, detection of "excess" internal noise sources, and extrapolation of flyover noise data from one flight speed to different flight speeds. Noise reduction of as much as 3 EPNdB was found with a deeply scalloped mixer compared to annular nozzle at net thrust levels of 9500 lb for a 29 in. diameter nozzle after optimizing the nozzle length.

  7. Automatic control design procedures for restructurable aircraft control

    NASA Technical Reports Server (NTRS)

    Looze, D. P.; Krolewski, S.; Weiss, J.; Barrett, N.; Eterno, J.

    1985-01-01

    A simple, reliable automatic redesign procedure for restructurable control is discussed. This procedure is based on Linear Quadratic (LQ) design methodologies. It employs a robust control system design for the unfailed aircraft to minimize the effects of failed surfaces and to extend the time available for restructuring the Flight Control System. The procedure uses the LQ design parameters for the unfailed system as a basis for choosing the design parameters of the failed system. This philosophy alloys the engineering trade-offs that were present in the nominal design to the inherited by the restructurable design. In particular, it alloys bandwidth limitations and performance trade-offs to be incorporated in the redesigned system. The procedure also has several other desirable features. It effectively redistributes authority among the available control effectors to maximize the system performance subject to actuator limitations and constraints. It provides a graceful performance degradation as the amount of control authority lessens. When given the parameters of the unfailed aircraft, the automatic redesign procedure reproduces the nominal control system design.

  8. Modeling of pulverized coal combustion processes in a vortex furnace of improved design. Part 1: Flow aerodynamics in a vortex furnace

    NASA Astrophysics Data System (ADS)

    Krasinsky, D. V.; Salomatov, V. V.; Anufriev, I. S.; Sharypov, O. V.; Shadrin, E. Yu.; Anikin, Yu. A.

    2015-02-01

    Some results of the complex experimental and numerical study of aerodynamics and transfer processes in a vortex furnace, whose design was improved via the distributed tangential injection of fuel-air flows through the upper and lower burners, were presented. The experimental study of the aerodynamic characteristics of a spatial turbulent flow was performed on the isothermal laboratory model (at a scale of 1 : 20) of an improved vortex furnace using a laser Doppler measurement system. The comparison of experimental data with the results of the numerical modeling of an isothermal flow for the same laboratory furnace model demonstrated their agreement to be acceptable for engineering practice.

  9. The application of aerodynamic uncertainties in the design of the entry trajectory and flight control system of the space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Gamble, J. D.

    1983-01-01

    The process used in the application of aerodynamic uncertainties for the design and verification of the Space Shuttle Orbiter Entry Flight Control System is presented. The uncertainties were used to help set center of gravity, angle of attack and dynamic pressure lateral control divergence parameter as well as C sub n sub beta dynamic were instrumental in setting these placards.

  10. Geometry Control System for Exploratory Shape Optimization Applied to High-Fidelity Aerodynamic Design of Unconventional Aircraft

    NASA Astrophysics Data System (ADS)

    Gagnon, Hugo

    This thesis represents a step forward to bring geometry parameterization and control on par with the disciplinary analyses involved in shape optimization, particularly high-fidelity aerodynamic shape optimization. Central to the proposed methodology is the non-uniform rational B-spline, used here to develop a new geometry generator and geometry control system applicable to the aerodynamic design of both conventional and unconventional aircraft. The geometry generator adopts a component-based approach, where any number of predefined but modifiable (parametric) wing, fuselage, junction, etc., components can be arbitrarily assembled to generate the outer mold line of aircraft geometry. A unique Python-based user interface incorporating an interactive OpenGL windowing system is proposed. Together, these tools allow for the generation of high-quality, C2 continuous (or higher), and customized aircraft geometry with fast turnaround. The geometry control system tightly integrates shape parameterization with volume mesh movement using a two-level free-form deformation approach. The framework is augmented with axial curves, which are shown to be flexible and efficient at parameterizing wing systems of arbitrary topology. A key aspect of this methodology is that very large shape deformations can be achieved with only a few, intuitive control parameters. Shape deformation consumes a few tenths of a second on a single processor and surface sensitivities are machine accurate. The geometry control system is implemented within an existing aerodynamic optimizer comprising a flow solver for the Euler equations and a sequential quadratic programming optimizer. Gradients are evaluated exactly with discrete-adjoint variables. The algorithm is first validated by recovering an elliptical lift distribution on a rectangular wing, and then demonstrated through the exploratory shape optimization of a three-pronged feathered winglet leading to a span efficiency of 1.22 under a height

  11. Tactical missile aerodynamics

    NASA Technical Reports Server (NTRS)

    Hemsch, Michael J. (Editor); Nielsen, Jack N. (Editor)

    1986-01-01

    The present conference on tactical missile aerodynamics discusses autopilot-related aerodynamic design considerations, flow visualization methods' role in the study of high angle-of-attack aerodynamics, low aspect ratio wing behavior at high angle-of-attack, supersonic airbreathing propulsion system inlet design, missile bodies with noncircular cross section and bank-to-turn maneuvering capabilities, 'waverider' supersonic cruise missile concepts and design methods, asymmetric vortex sheding phenomena from bodies-of-revolution, and swept shock wave/boundary layer interaction phenomena. Also discussed are the assessment of aerodynamic drag in tactical missiles, the analysis of supersonic missile aerodynamic heating, the 'equivalent angle-of-attack' concept for engineering analysis, the vortex cloud model for body vortex shedding and tracking, paneling methods with vorticity effects and corrections for nonlinear compressibility, the application of supersonic full potential method to missile bodies, Euler space marching methods for missiles, three-dimensional missile boundary layers, and an analysis of exhaust plumes and their interaction with missile airframes.

  12. Quiet Clean Short-haul Experimental Engine (QCSEE): The aerodynamic and mechanical design of the QCSEE under-the-wing fan

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The design, fabrication, and testing of two experimental high bypass geared turbofan engines and propulsion systems for short haul passenger aircraft are described. The aerodynamic and mechanical design of a variable pitch 1.34 pressure ratio fan for the under the wing (UTW) engine are included. The UTW fan was designed to permit rotation of the 18 composite fan blades into the reverse thrust mode of operation through both flat pitch and stall pitch directions.

  13. Aerodynamic performance of conventional and advanced design labyrinth seals with solid-smooth abradable, and honeycomb lands. [gas turbine engines

    NASA Technical Reports Server (NTRS)

    Stocker, H. L.; Cox, D. M.; Holle, G. F.

    1977-01-01

    Labyrinth air seal static and dynamic performance was evaluated using solid, abradable, and honeycomb lands with standard and advanced seal designs. The effects on leakage of land surface roughness, abradable land porosity, rub grooves in abradable lands, and honeycomb land cell size and depth were studied using a standard labyrinth seal. The effects of rotation on the optimum seal knife pitch were also investigated. Selected geometric and aerodynamic parameters for an advanced seal design were evaluated to derive an optimized performance configuration. The rotational energy requirements were also measured to determine the inherent friction and pumping energy absorbed by the various seal knife and land configurations tested in order to properly assess the net seal system performance level. Results indicate that: (1) seal leakage can be significantly affected with honeycomb or abradable lands; (2) rotational energy absorption does not vary significantly with the use of a solid-smooth, an abradable, or a honeycomb land; and (3) optimization of an advanced lab seal design produced a configuration that had leakage 25% below a conventional stepped seal.

  14. Numerical methods and a computer program for subsonic and supersonic aerodynamic design and analysis of wings with attainable thrust considerations

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.; Walkley, K. B.

    1984-01-01

    This paper describes methodology and an associated computer program for the design of wing lifting surfaces with attainable thrust taken into consideration. The approach is based on the determination of an optimum combination of a series of candidate surfaces rather than the more commonly used candidate loadings. Special leading-edge surfaces are selected to provide distributed leading-edge thrust forces which compensate for any failure to achieve the full theoretical leading-edge thrust, and a second series of general candidate surfaces is selected to minimize drag subject to constraints on the lift coefficient and, if desired, on the pitching moment coefficient. A primary purpose of the design approach is the introduction of attainable leading-edge thrust considerations so that relatively mild camber surfaces may be employed in the achievement of aerodynamic efficiencies comparable to those attainable if full theoretical leading-edge thrust could be achieved. The program provides an analysis as well as a design capability and is applicable to both subsonic and supersonic flow.

  15. Procedural design considerations associated with tubing-conveyed underbalanced perforating

    SciTech Connect

    Young, W.S.; Zaleski, T.E.

    1985-03-01

    Thirty-two tubing conveyed underbalanced perforating jobs conducted in the Gulf of Mexico between May, 1980, and May, 1982, have been carefully reviewed in order to draw correlations between procedural variations and trouble prone jobs. General procedural guidelines designed to avoid past problems were formulated and are presented. The procedures are designed for the generalized case where the perforating guns will be pulled out of the well in order to gravel pack and not for those run as part of a permanent completion. Careful application of these procedural guidelines has resulted in reducing rig time requirements by an average of 35% on 33 additional tubing conveyed underbalanced perforating jobs conducted subsequent to the establishment of the guidelines contained in this paper.

  16. Multilevel decomposition approach to integrated aerodynamic/dynamic/structural optimization of helicopter rotor blades

    NASA Technical Reports Server (NTRS)

    Walsh, Joanne L.; Young, Katherine C.; Pritchard, Jocelyn I.; Adelman, Howard M.; Mantay, Wayne R.

    1994-01-01

    This paper describes an integrated aerodynamic, dynamic, and structural (IADS) optimization procedure for helicopter rotor blades. The procedure combines performance, dynamics, and structural analyses with a general purpose optimizer using multilevel decomposition techniques. At the upper level, the structure is defined in terms of local quantities (stiffnesses, mass, and average strains). At the lower level, the structure is defined in terms of local quantities (detailed dimensions of the blade structure and stresses). The IADS procedure provides an optimization technique that is compatible with industrial design practices in which the aerodynamic and dynamic design is performed at a global level and the structural design is carried out at a detailed level with considerable dialogue and compromise among the aerodynamic, dynamic, and structural groups. The IADS procedure is demonstrated for several cases.

  17. Integrated aerodynamic/dynamic/structural optimization of helicopter rotor blades using multilevel decomposition

    NASA Technical Reports Server (NTRS)

    Walsh, Joanne L.; Young, Katherine C.; Pritchard, Jocelyn I.; Adelman, Howard M.; Mantay, Wayne R.

    1995-01-01

    This paper describes an integrated aerodynamic/dynamic/structural (IADS) optimization procedure for helicopter rotor blades. The procedure combines performance, dynamics, and structural analyses with a general-purpose optimizer using multilevel decomposition techniques. At the upper level, the structure is defined in terms of global quantities (stiffness, mass, and average strains). At the lower level, the structure is defined in terms of local quantities (detailed dimensions of the blade structure and stresses). The IADS procedure provides an optimization technique that is compatible with industrial design practices in which the aerodynamic and dynamic designs are performed at a global level and the structural design is carried out at a detailed level with considerable dialog and compromise among the aerodynamic, dynamic, and structural groups. The IADS procedure is demonstrated for several examples.

  18. Aerodynamic design of the Cal Poly Da Vinci Human-Powered Helicopter

    NASA Technical Reports Server (NTRS)

    Larwood, Scott; Saiki, Neal

    1990-01-01

    This paper will discuss the methodology used in designing the rotor and drive propellers for the third generation Cal Poly Da Vinci Human-Powered Helicopter. The rotor was designed using a lifting surface, uniform inflow hover analysis code and the propeller was designed using a minimum induced-loss method. Construction, geometry, and operating considerations are discussed as they impact the designs. Optimization of the design performance is also explained. The propellers were tested in a wind tunnel and results are compared with theoretical data. Successful flight tests of the Da Vinci III are discussed.

  19. Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.

    1989-01-01

    Progress in the direct-inverse wing design method in curvilinear coordinates has been made. This includes the remedying of a spanwise oscillation problem and the assessment of grid skewness, viscous interaction, and the initial airfoil section on the final design. It was found that, in response to the spanwise oscillation problem that designing at every other spanwise station produced the best results for the cases presented, a smoothly varying grid is especially needed for the accurate design at the wing tip, the boundary layer displacement thicknesses must be included in a successful wing design, the design of high and medium aspect ratio wings is possible with this code, and the final airfoil section designed is fairly independent of the initial section.

  20. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: experimental design and preliminary results.

    PubMed

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed. PMID:25430144

  1. An analytical framework for the design and comparative analysis of galloping energy harvesters under quasi-steady aerodynamics

    NASA Astrophysics Data System (ADS)

    Bibo, Amin; Daqaq, Mohammed F.

    2015-09-01

    This paper presents a generalized formulation, analysis, and optimization of energy harvesters subjected to galloping and base excitations. The harvester consists of a cantilever beam with a bluff body attached at the free end. A nondimensional lumped-parameter model which accounts for the combined loading and different electro-mechanical transduction mechanisms is presented. The aerodynamic loading is modeled using the quasi-steady assumption with polynomial approximation. A nonlinear analysis is carried out and an approximate analytical solution is obtained. A dimensional analysis is performed to identify the important parameters that affect the system's response. The analysis of the response is divided into two parts. The first treats a harvester subjected to only galloping excitations. It is shown that, for a given shape of the bluff body and under quasi-steady flow conditions, the harvester's dimensionless response can be described by a single universal curve irrespective to the geometric, mechanical, and electrical design parameters of the harvester. In the second part, a harvester under concurrent galloping and base excitations is analyzed. It is shown that, the total output power depends on three dimensionless loading parameters; wind speed, base excitation amplitude, and excitation frequency. The response curves of the harvester are generated in terms of the loading parameters. These curves can serve as a complete design guide for scaling and optimizing the performance of galloping-based harvesters.

  2. Aerodynamic design of turbomachinery blading in three-dimensional flow - An application to radial inflow turbines

    NASA Technical Reports Server (NTRS)

    Yang, Y. L.; Tan, C. S.; Hawthorne, W. R.

    1992-01-01

    A computational method, based on a theory for turbomachinery blading design in three-dimensional inviscid flow, is applied to a parametric design study of a radial inflow turbine wheel. As the method requires the specification of swirl distribution, a technique for its smooth generation within the blade region is proposed. Excellent agreements have been obtained between the computed results from this design method and those from direct Euler computations, demonstrating the correspondence and consistency between the two. The computed results indicate the sensitivity of the pressure distribution to a lean in the stacking axis and a minor alteration in the hub/shroud profiles. Analysis based on Navier-Stokes solver shows no breakdown of flow within the designed blade passage and agreement with that from design calculation; thus the flow in the designed turbine rotor closely approximates that of an inviscid one. These calculations illustrate the use of a design method coupled to an analysis tool for establishing guidelines and criteria for designing turbomachinery blading.

  3. Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.

    1989-01-01

    An inverse wing design method was developed around an existing transonic wing analysis code. The original analysis code, TAWFIVE, has as its core the numerical potential flow solver, FLO30, developed by Jameson and Caughey. Features of the analysis code include a finite-volume formulation; wing and fuselage fitted, curvilinear grid mesh; and a viscous boundary layer correction that also accounts for viscous wake thickness and curvature. The development of the inverse methods as an extension of previous methods existing for design in Cartesian coordinates is presented. Results are shown for inviscid wing design cases in super-critical flow regimes. The test cases selected also demonstrate the versatility of the design method in designing an entire wing or discontinuous sections of a wing.

  4. Aerodynamics Improve Wind Wheel

    NASA Technical Reports Server (NTRS)

    Ramsey, V. W.

    1982-01-01

    Modifications based on aerodynamic concepts would raise efficiency of wind-wheel electric-power generator. Changes smooth airflow, to increase power output, without increasing size of wheel. Significant improvements in efficiency anticipated without any increase in size or number of moving parts and without departing from simplicity of original design.

  5. Supersonic aerodynamics of delta wings

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.

    1988-01-01

    Through the empirical correlation of experimental data and theoretical analysis, a set of graphs has been developed which summarize the inviscid aerodynamics of delta wings at supersonic speeds. The various graphs which detail the aerodynamic performance of delta wings at both zero-lift and lifting conditions were then employed to define a preliminary wing design approach in which both the low-lift and high-lift design criteria were combined to define a feasible design space.

  6. Study of blade aspect ratio on a compressor front stage aerodynamic and mechanical design report

    NASA Technical Reports Server (NTRS)

    Burger, G. D.; Lee, D.; Snow, D. W.

    1979-01-01

    A single stage compressor was designed with the intent of demonstrating that, for a tip speed and hub-tip ratio typical of an advanced core compressor front stage, the use of low aspect ratio can permit high levels of blade loading to be achieved at an acceptable level of efficiency. The design pressure ratio is 1.8 at an adiabatic efficiency of 88.5 percent. Both rotor and stator have multiple-circular-arc airfoil sections. Variable IGV and stator vanes permit low speed matching adjustments. The design incorporates an inlet duct representative of an engine transition duct between fan and high pressure compressor.

  7. The use of artificial neural networks in experimental data acquisition and aerodynamic design

    NASA Technical Reports Server (NTRS)

    Meade, Andrew J., Jr.

    1991-01-01

    It is proposed that an artificial neural network be used to construct an intelligent data acquisition system. The artificial neural networks (ANN) model has a potential for replacing traditional procedures as well as for use in computational fluid dynamics validation. Potential advantages of the ANN model are listed. As a proof of concept, the author modeled a NACA 0012 airfoil at specific conditions, using the neural network simulator NETS, developed by James Baffes of the NASA Johnson Space Center. The neural network predictions were compared to the actual data. It is concluded that artificial neural networks can provide an elegant and valuable class of mathematical tools for data analysis.

  8. A system for aerodynamic design and analysis of supersonic aircraft. Part 3: Computer program description

    NASA Technical Reports Server (NTRS)

    Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

    1980-01-01

    The computer program documentation for the design and analysis of supersonic configurations is presented. Schematics and block diagrams of the major program structure, together with subroutine descriptions for each module are included.

  9. Study of controlled diffusion stator blading. 1. Aerodynamic and mechanical design report

    NASA Technical Reports Server (NTRS)

    Canal, E.; Chisholm, B. C.; Lee, D.; Spear, D. A.

    1981-01-01

    Pratt & Whitney Aircraft is conducting a test program for NASA in order to demonstrate that a controlled-diffusion stator provides low losses at high loadings and Mach numbers. The technology has shown great promise in wind tunnel tests. Details of the design of the controlled diffusion stator vanes and the multiple-circular-arc rotor blades are presented. The stage, including stator and rotor, was designed to be suitable for the first-stage of an advanced multistage, high-pressure compressor.

  10. 40 CFR 228.4 - Procedures for designation of sites.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... 228.4 Section 228.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE MANAGEMENT OF DISPOSAL SITES FOR OCEAN DUMPING § 228.4 Procedures for designation... permits. Areas where ocean dumping is permitted subject to the specific conditions of individual...

  11. 40 CFR 228.4 - Procedures for designation of sites.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... 228.4 Section 228.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE MANAGEMENT OF DISPOSAL SITES FOR OCEAN DUMPING § 228.4 Procedures for designation... permits. Areas where ocean dumping is permitted subject to the specific conditions of individual...

  12. 40 CFR 228.4 - Procedures for designation of sites.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... 228.4 Section 228.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE MANAGEMENT OF DISPOSAL SITES FOR OCEAN DUMPING § 228.4 Procedures for designation... permits. Areas where ocean dumping is permitted subject to the specific conditions of individual...

  13. 40 CFR 240.201-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... carcasses, automobile bodies, dewatered sludges from water treatment plants, and industrial process wastes. ... WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures... or excluded wastes inadvertently left at the facility should be considered in design. (b) Examples...

  14. Integral flange design program. [procedure for computing stresses

    NASA Technical Reports Server (NTRS)

    Wilson, J. F.

    1974-01-01

    An automated interactive flange design program utilizing an electronic desk top calculator is presented. The program calculates the operating and seating stresses for circular flanges of the integral or optional type subjected to internal pressure. The required input information is documented. The program provides an automated procedure for computing stresses in selected flange geometries for comparison to the allowable code values.

  15. A SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation and analysis of multiple objectives are very important in designing environmentally benign processes. They require a systematic procedure for solving multi-objective decision-making problems due to the complex nature of the problems and the need for complex assessment....

  16. 40 CFR 228.4 - Procedures for designation of sites.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DUMPING CRITERIA FOR THE MANAGEMENT OF DISPOSAL SITES FOR OCEAN DUMPING § 228.4 Procedures for designation... permits. Areas where ocean dumping is permitted subject to the specific conditions of individual special... studies for the evaluation and potential selection of dumping sites will be conducted in accordance...

  17. Handbook of Procedures for the Design of Instruction.

    ERIC Educational Resources Information Center

    Briggs, Leslie J.

    Instruction can be systematically designed using the procedures, or model, set forth in this handbook. Steps are given for writing, selecting, and organizing behavioral objectives and for identifying their levels. Test construction, testing, and grading are explained. Flowcharts illustrate how to determine required competencies and actual entering…

  18. 40 CFR 240.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Environmental factors, climatological conditions, and socioeconomic factors should be given full consideration... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Recommended procedures: Design. 240.202-2 Section 240.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  19. 40 CFR 240.202-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Design. 240.202-2 Section 240.202-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID...) The site should be accessible by permanent roads leading from the public road system....

  20. Supersonic aerodynamic trade data for a low-profile monoplanar missile concept. [air launched maneuvering missile design

    NASA Technical Reports Server (NTRS)

    Graves, E. B.; Robins, A. W.

    1979-01-01

    A monoplanar missile concept has been studied which shows promise of improving the aerodynamic performance of air-launched missiles. This missile concept has a constant eccentricity elliptical cross-section body. Since current guidance and propulsion technologies influence missile nose and base shapes, an experimental investigation has been conducted at Mach number 2.50 to determine the effects of variations in these shapes on the missile aerodynamics. Results of these tests are presented.

  1. Low-speed aerodynamic characteristics of a 16-percent-thick variable-geometry airfoil designed for general aviation applications

    NASA Technical Reports Server (NTRS)

    Barnwell, R. W.; Noonan, K. W.; Mcghee, R. J.

    1978-01-01

    Tests were conducted in the Langley low-turbulence pressure tunnel to determine the aerodynamic characteristics of climb, cruise, and landing configurations. These tests were conducted over a Mach number range from 0.10 to 0.35, a chord Reynolds number range from 2.0 x 1 million to 20.0 x 1 million, and an angle-of-attack range from -8 deg to 20 deg. Results show that the maximum section lift coefficients increased in the Reynolds number range from 2.0 x 1 million to 9.0 x 1 million and reached values of approximately 2.1, 1.8, and 1.5 for the landing, climb, and cruise configurations, respectively. Stall characteristics, although of the trailing-edge type, were abrupt. The section lift-drag ratio of the climb configuration with fixed transition near the leading edge was about 78 at a lift coefficient of 0.9, a Mach number of 0.15, and a Reynolds number of 4.0 x 1 million. Design lift coefficients of 0.9 and 0.4 for the climb and cruise configurations were obtained at the same angle of attack, about 6 deg, as intended. Good agreement was obtained between experimental results and the predictions of a viscous, attached-flow theoretical method.

  2. An aerodynamic investigation of two 1.83-meter-diameter fan systems designed to drive a subsonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Page, V. R.; Eckert, W. T.; Mort, K. W.

    1977-01-01

    An experimental, aerodynamic investigation was made of two 1.83 m diameter fan systems which are being considered for the repowered drive section of the 40- by 80-foot wind tunnel at NASA Ames Research Center. One system was low speed, the other was high speed. The low speed fan was tested at various stagger angles from 32.9 deg to 62.9 deg. At a fan blade stagger angle of 40.8 deg and operating at a tip speed of 1155 m/sec, the low speed fan developed 207.3 m of head. The high speed fan had a design blade stagger angle of 56.2 deg and was tested at this stagger angle only. The high speed fan operating at 191.5 m/sec developed 207.3 m of head. Radial distributions of static pressure coefficients, total pressure coefficients, and angles of swirl are presented. Radial surveys were conducted at four azimuth locations in front of the fan, and repeated downstream of the fan. Data were taken for various flow control devices and for two inlet contraction lengths.

  3. Aerodynamic and Structural Design of MultiMW Wind Turbine Blades beyond 5MW

    NASA Astrophysics Data System (ADS)

    Hillmer, B.; Borstelmann, T.; Schaffarczyk, P. A.; Dannenberg, L.

    2007-07-01

    A unified approach was taken to the design of wind-turbine blades for multiMW machines up to 10 MW. Using input from standard existing machines, three baseline versions were designed. Then - after up-scaling - using the aero-elastic code FLEX5 a typical extreme load case was selected. As a result, weights seem to increase more than might be expected by an empirical law deduced from statistical data. However, some further investigations are needed, e. g. buckling and fatigue analyses. The authors regard the method developed here as a useful approach for pre-design investigation. One important aspect seems to be the need for high-quality GRPs, with admissible strength of more than 120 MPa.

  4. Two stage low noise advanced technology fan. 1: Aerodynamic, structural, and acoustic design

    NASA Technical Reports Server (NTRS)

    Messenger, H. E.; Ruschak, J. T.; Sofrin, T. G.

    1974-01-01

    A two-stage fan was designed to reduce noise 20 db below current requirements. The first-stage rotor has a design tip speed of 365.8 m/sec and a hub/tip ratio of 0.4. The fan was designed to deliver a pressure ratio of 1.9 with an adiabatic efficiency of 85.3 percent at a specific inlet corrected flow of 209.2kg/sec/sq m. Noise reduction devices include acoustically treated casing walls, a flowpath exit acoustic splitter, a translating centerbody sonic inlet device, widely spaced blade rows, and the proper ratio of blades and vanes. Multiple-circular-arc rotor airfoils, resettable stators, split outer casings, and capability to go to close blade-row spacing are also included.

  5. Computerized three-dimensional aerodynamic design of a lifting rotor blade

    NASA Technical Reports Server (NTRS)

    Tauber, M. E.; Hicks, R. M.

    1980-01-01

    A three-dimensional, inviscid, full-potential lifting rotor code was used to demonstrate that pressure distributions on both advancing and retreating blades could be significantly improved by perturbing local airfoil sections. The perturbations were described by simple geometric shape functions. To illustrate the procedure, an example calculation was made at a forward flight speed of 85 m/sec (165 knots) and an advance ratio of 0.385. It was found that a minimum of three shape functions was required to improve the pressures without producing undesirable secondary effects in high-speed forward flight on a hypothetical modern rotor blade initially having an NLR-1 supercritical airfoil. Reductions in the shock strength on the advancing blade could be achieved, while simultaneously lessening leading-edge pressure gradients on the retreating blade. The major blade section modifications required were blunting of the upper surface leading edge and some reshaping of the blade's upper surface resulting in moderately thicker airfoils.

  6. Aerodynamic design and analysis system for supersonic aircraft. Part 3: Computer program description

    NASA Technical Reports Server (NTRS)

    Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

    1975-01-01

    The computer program for the design and analysis of supersonic aircraft configurations is presented. The schematics of the program structure are provided. The individual overlays and subroutines are described. The system is useful in determining surface pressures and supersonic area rule concepts.

  7. Aerodynamic optimization, comparison, and trim design of canard and conventional high performance general aviation configurations

    NASA Technical Reports Server (NTRS)

    Keith, M. W.; Selberg, B. P.

    1983-01-01

    A design study has been conducted to optimize trim cruise flight of high performance general aviation canard aircraft which achieve minimum drag. In order to investigate the advantages and disadvantages of canard configured aircraft, corresponding conventional tail-aft 'baseline' aircraft were designed and used for comparison. Two-dimensional predictions were obtained by coupling inviscid results from a vortex panel multi-element program to a momentum integral boundary layer analysis. Using the results of the two-dimensional vortex panel analysis, a vortex lattice method was employed to predict the finite wing results. The analysis utilized a turbulent airfoil and a natural laminar airfoil which are two NASA state-of-the-art airfoil sections. The canard aircraft designs give quantitative results of wing and canard loadings, wing-to-canard moment arm ratios, and aspect ratio effects for trim cruise flight for a wide range of wing-to-canard area ratios. Both canard and baseline aircraft achieved a 25 to 30 percent improvement in performance over typical current technology aircraft, but high canard loading necessary for trim resulted in slightly poorer performance of the canard aircraft as compared to the baseline designs.

  8. The aerodynamic challenges of SRB recovery

    NASA Technical Reports Server (NTRS)

    Bacchus, D. L.; Kross, D. A.; Moog, R. D.

    1985-01-01

    Recovery and reuse of the Space Shuttle solid rocket boosters was baselined to support the primary goal to develop a low cost space transportation system. The recovery system required for the 170,000-lb boosters was for the largest and heaviest object yet to be retrieved from exoatmospheric conditions. State-of-the-art design procedures were ground-ruled and development testing minimized to produce both a reliable and cost effective system. The ability to utilize the inherent drag of the boosters during the initial phase of reentry was a key factor in minimizing the parachute loads, size and weight. A wind tunnel test program was devised to enable the accurate prediction of booster aerodynamic characteristics. Concurrently, wind tunnel, rocket sled and air drop tests were performed to develop and verify the performance of the parachute decelerator subsystem. Aerodynamic problems encountered during the overall recovery system development and the respective solutions are emphasized.

  9. Aerodynamic design and performance testing of an advanced 30 deg swept, eight bladed propeller at Mach numbers from 0.2 to 0.85

    NASA Technical Reports Server (NTRS)

    Black, D. M.; Menthe, R. W.; Wainauski, H. S.

    1978-01-01

    The increased emphasis on fuel conservation in the world has stimulated a series of studies of both conventional and unconventional propulsion systems for commercial aircraft. Preliminary results from these studies indicate that a fuel saving of from 15 to 28 percent may be realized by the use of an advanced high speed turboprop. The turboprop must be capable of high efficiency at Mach 0.8 above 10.68 km (35,000 ft) altitude if it is to compete with turbofan powered commercial aircraft. An advanced turboprop concept was wind tunnel tested. The model included such concepts as an aerodynamically integrated propeller/nacelle, blade sweep and power (disk) loadings approximately three times higher than conventional propeller designs. The aerodynamic design for the model is discussed. Test results are presented which indicate propeller net efficiencies near 80 percent were obtained at high disk loadings at Mach 0.8.

  10. Aerodynamics design of two-stage vane-less counter-rotating turbinec

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Liu, Huoxing; Li, Wei; Zeng, Jun

    2011-10-01

    It is one of the most efficient ways to greatly improve aero-engines' performance by utilizing vaneless counter-rotating turbine (VCRT) technology. To supply sufficient power, VCRT turns to be high Mach number, large flow angle at high-pressure turbine (HPT) rotor exit, and low blade camber angle, which increase difficulties to turbine design. As the axial velocity ratio of HPT rotor is much larger than the conventional ones, the optimal selection of VCRT velocity triangles based on theoretical analysis is developed, and how the efficiency varied by HPT stator/rotor exit flow angle is also figured out. The key points to design a high efficient practicable VCRT are to select velocity triangles that are characterized by low flow coefficient, high outlet flow angle and large axial velocity ratio of HPT rotor. Meanwhile, performance comparison between convergent blade and convergent-divergent blade shows the latter is more appropriate for VCRT.

  11. Aerodynamic Design of Axial-Flow Compressors. VII - Blade-Element Flow in Annular Cascades

    NASA Technical Reports Server (NTRS)

    Robbins, William H.; Jackson, Robert J.; Lieblein, Seymour

    1955-01-01

    Annular blade-element data obtained primarily from single-stage compressor installations are correlated over a range of inlet Mach numbers and cascade geometry. The correlation curves are presented in such a manner that they are related directly to the low-speed two-dimensional-cascade data of part VI of this series. Thus, the data serve as both an extension and a verification of the two-dimensional-cascade data. In addition, the correlation results are applied to compressor design.

  12. Aerodynamics of Race Cars

    NASA Astrophysics Data System (ADS)

    Katz, Joseph

    2006-01-01

    Race car performance depends on elements such as the engine, tires, suspension, road, aerodynamics, and of course the driver. In recent years, however, vehicle aerodynamics gained increased attention, mainly due to the utilization of the negative lift (downforce) principle, yielding several important performance improvements. This review briefly explains the significance of the aerodynamic downforce and how it improves race car performance. After this short introduction various methods to generate downforce such as inverted wings, diffusers, and vortex generators are discussed. Due to the complex geometry of these vehicles, the aerodynamic interaction between the various body components is significant, resulting in vortex flows and lifting surface shapes unlike traditional airplane wings. Typical design tools such as wind tunnel testing, computational fluid dynamics, and track testing, and their relevance to race car development, are discussed as well. In spite of the tremendous progress of these design tools (due to better instrumentation, communication, and computational power), the fluid dynamic phenomenon is still highly nonlinear, and predicting the effect of a particular modification is not always trouble free. Several examples covering a wide range of vehicle shapes (e.g., from stock cars to open-wheel race cars) are presented to demonstrate this nonlinear nature of the flow field.

  13. Aerodynamic design guidelines and computer program for estimation of subsonic wind tunnel performance

    NASA Technical Reports Server (NTRS)

    Eckert, W. T.; Mort, K. W.; Jope, J.

    1976-01-01

    General guidelines are given for the design of diffusers, contractions, corners, and the inlets and exits of non-return tunnels. A system of equations, reflecting the current technology, has been compiled and assembled into a computer program (a user's manual for this program is included) for determining the total pressure losses. The formulation presented is applicable to compressible flow through most closed- or open-throat, single-, double-, or non-return wind tunnels. A comparison of estimated performance with that actually achieved by several existing facilities produced generally good agreement.

  14. Integration of Rotor Aerodynamic Optimization with the Conceptual Design of a Large Civil Tiltrotor

    NASA Technical Reports Server (NTRS)

    Acree, C. W., Jr.

    2010-01-01

    Coupling of aeromechanics analysis with vehicle sizing is demonstrated with the CAMRAD II aeromechanics code and NDARC sizing code. The example is optimization of cruise tip speed with rotor/wing interference for the Large Civil Tiltrotor (LCTR2) concept design. Free-wake models were used for both rotors and the wing. This report is part of a NASA effort to develop an integrated analytical capability combining rotorcraft aeromechanics, structures, propulsion, mission analysis, and vehicle sizing. The present paper extends previous efforts by including rotor/wing interference explicitly in the rotor performance optimization and implicitly in the sizing.

  15. Design and Predictions for a High-Altitude (Low-Reynolds-Number) Aerodynamic Flight Experiment

    NASA Technical Reports Server (NTRS)

    Greer, Donald; Hamory, Phil; Krake, Keith; Drela, Mark

    1999-01-01

    A sailplane being developed at NASA Dryden Flight Research Center will support a high-altitude flight experiment. The experiment will measure the performance parameters of an airfoil at high altitudes (70,000 to 100,000 ft), low Reynolds numbers (200,000 to 700,000), and high subsonic Mach numbers (0.5 and 0.65). The airfoil section lift and drag are determined from pitot and static pressure measurements. The locations of the separation bubble, Tollmien-Schlichting boundary layer instability frequencies, and vortex shedding are measured from a hot-film strip. The details of the planned flight experiment are presented. Several predictions of the airfoil performance are also presented. Mark Drela from the Massachusetts Institute of Technology designed the APEX-16 airfoil, using the MSES code. Two-dimensional Navier-Stokes analyses were performed by Mahidhar Tatineni and Xiaolin Zhong from the University of California, Los Angeles, and by the authors at NASA Dryden.

  16. On the design of flight-deck procedures

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Wiener, Earl L.

    1994-01-01

    In complex human-machine systems, operations, training, and standardization depend on a elaborate set of procedures which are specified and mandated by the operational management of the organization. The intent is to provide guidance to the pilots, to ensure a logical, efficient, safe, and predictable means of carrying out the mission objectives. In this report the authors examine the issue of procedure use and design from a broad viewpoint. The authors recommend a process which we call 'The Four P's:' philosophy, policies, procedures, and practices. We believe that if an organization commits to this process, it can create a set of procedures that are more internally consistent, less confusing, better respected by the flight crews, and that will lead to greater conformity. The 'Four-P' model, and the guidelines for procedural development in appendix 1, resulted from cockpit observations, extensive interviews with airline management and pilots, interviews and discussion at one major airframe manufacturer, and an examination of accident and incident reports. Although this report is based on airline operations, we believe that the principles may be applicable to other complex, high-risk systems, such as nuclear power production, manufacturing process control, space flight, and military operations.

  17. A computer aided design procedure for generating gear teeth

    NASA Technical Reports Server (NTRS)

    Chang, S. H.; Huston, R. L.; Coy, J. J.

    1984-01-01

    A procedure for computer aided design (CAD) of gear teeth is presented. It is developed for generated teeth fabricated by a hob cutter or a shaper. It provides a means for analytically and numerically determining the tooth profile, given the cutter profile. An illustrative example with involute tooth profiles is given. Application with non-standard profiles and with bevel, spiral bevel, and hypoid gears is discussed.

  18. The Design of Cruciform Test Specimens for Planar Biaxial Testing of Fabrics for Inflatable Aerodynamic Decelerators

    NASA Technical Reports Server (NTRS)

    Corbin, Cole K.

    2012-01-01

    A preliminary analytical study was conducted to investigate the effects of cruciform test specimen geometries on strain distribution uniformity in the central gage section under biaxial loads. Three distinct specimen geometries were considered while varying the applied displacements in the two orthogonal directions. Two sets of woven fabric material properties found in literature were used to quantify the influence of specimen geometries on the resulting strain distributions. The uniformity of the strain distribution is quantified by taking the ratio between the two orthogonal strain components and characterizing its gradient across the central area of the gage section. The analysis results show that increasing the specimen s length relative to its width promotes a more uniform strain distribution in the central section of the cruciform test specimen under equibiaxial enforced tensile displacements. However, for the two sets of material properties used in this study, this trend did not necessary hold, when the enforced tensile displacements in the two orthogonal directions were not equal. Therefore, based on the current study, a tail length that is 1.5 times that of the tail width is recommended to be the baseline/initial specimen design.

  19. Equating designs and procedures used in Rasch scaling.

    PubMed

    Skaggs, Gary; Wolfe, Edward W

    2010-01-01

    The development of alternate forms of tests requires a statistical score adjustment called equating that permits the interchanging of scores from different test forms. Equating makes possible several important measurement applications, including removing practice effects in pretest-posttest research designs, improving test security, comparing scores between new and old forms, and supporting item bank development for computerized adaptive testing. This article summarizes equating methods from a Rasch measurement perspective. The four sections of this article present an introduction and definition of equating and related linking methods, data collection designs, equating procedures, and evaluating equated measures. The methods are illustrated with worked examples. PMID:20693702

  20. A Formal Approach for Designing and Evaluating Procedures

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael; Shafto, Michael; Remington, Roger (Technical Monitor)

    1998-01-01

    Operator interaction with modern control systems is a topic of great concern in high-risk industries such as nuclear power and commercial aviation. The issues associated with such systems focus on the ability of the operators (e.g., pilots) to achieve mission goals safely while containing failures. Operators must be able to interact safely and reliably with highly automatic and complex systems across the full spectrum of possible operating conditions, including normal, abnormal, and emergency situations. In environments such as commercial aviation, operator interaction with the machine is specified through a set of standard operating procedures (SOP). A procedure represents a collective agreement on the 'best' way to perform a given task. The intent of this paper is to suggest a formal methodology, for designing and evaluating procedures, that is both reliable and systematic. Our approach involves two major elements: a model of the machine and a list of the operator's task specifications (goals). We use formal modeling paradigms for describing the system and super-imposing on it the operator's tasks. Such paradigms, based on recent frameworks such as Statecharts and Hierarchical Hybrid Machines appear to be adequate methods for analyzing operator interaction with modern control systems. To illustrate this methodology, we model and analyze the sequence of actions for an emergency procedure. The procedure, Irregular Engine Start, for a medium-range aircraft, specifies the sequence of immediate actions that must be performed by the crew to avoid an uncontrolled rise in engine temperature during start-up. A model of engine behavior during a hot start is constructed. It also describes the various actions that can be taken by the crew and the resulting outcomes. The model is then opened up as a tree of all possible action sequences. This action tree allows us to trace the correct sequences necessary to achieve the desired end-goal (secure and shut down of the engine). In

  1. PREFACE: Aerodynamic sound Aerodynamic sound

    NASA Astrophysics Data System (ADS)

    Akishita, Sadao

    2010-02-01

    The modern theory of aerodynamic sound originates from Lighthill's two papers in 1952 and 1954, as is well known. I have heard that Lighthill was motivated in writing the papers by the jet-noise emitted by the newly commercialized jet-engined airplanes at that time. The technology of aerodynamic sound is destined for environmental problems. Therefore the theory should always be applied to newly emerged public nuisances. This issue of Fluid Dynamics Research (FDR) reflects problems of environmental sound in present Japanese technology. The Japanese community studying aerodynamic sound has held an annual symposium since 29 years ago when the late Professor S Kotake and Professor S Kaji of Teikyo University organized the symposium. Most of the Japanese authors in this issue are members of the annual symposium. I should note the contribution of the two professors cited above in establishing the Japanese community of aerodynamic sound research. It is my pleasure to present the publication in this issue of ten papers discussed at the annual symposium. I would like to express many thanks to the Editorial Board of FDR for giving us the chance to contribute these papers. We have a review paper by T Suzuki on the study of jet noise, which continues to be important nowadays, and is expected to reform the theoretical model of generating mechanisms. Professor M S Howe and R S McGowan contribute an analytical paper, a valuable study in today's fluid dynamics research. They apply hydrodynamics to solve the compressible flow generated in the vocal cords of the human body. Experimental study continues to be the main methodology in aerodynamic sound, and it is expected to explore new horizons. H Fujita's study on the Aeolian tone provides a new viewpoint on major, longstanding sound problems. The paper by M Nishimura and T Goto on textile fabrics describes new technology for the effective reduction of bluff-body noise. The paper by T Sueki et al also reports new technology for the

  2. Advanced Aerodynamic Control Effectors

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.

    1999-01-01

    A 1990 research program that focused on the development of advanced aerodynamic control effectors (AACE) for military aircraft has been reviewed and summarized. Data are presented for advanced planform, flow control, and surface contouring technologies. The data show significant increases in lift, reductions in drag, and increased control power, compared to typical aerodynamic designs. The results presented also highlighted the importance of planform selection in the design of a control effector suite. Planform data showed that dramatic increases in lift (greater than 25%) can be achieved with multiple wings and a sawtooth forebody. Passive porosity and micro drag generator control effector data showed control power levels exceeding that available from typical effectors (moving surfaces). Application of an advanced planform to a tailless concept showed benefits of similar magnitude as those observed in the generic studies.

  3. Advanced missile technology. A review of technology improvement areas for cruise missiles. [including missile design, missile configurations, and aerodynamic characteristics

    NASA Technical Reports Server (NTRS)

    Cronvich, L. L.; Liepman, H. P.

    1979-01-01

    Technology assessments in the areas of aerodynamics, propulsion, and structures and materials for cruise missile systems are discussed. The cruise missiles considered cover the full speed, altitude, and target range. The penetrativity, range, and maneuverability of the cruise missiles are examined and evaluated for performance improvements.

  4. The LQR/LTR procedure for multivariable feedback control design

    NASA Technical Reports Server (NTRS)

    Stein, Gunter; Athans, Michael

    1987-01-01

    This paper provides a tutorial overview of the linear quadratic Gaussian with loop transfer recovery (LQG/LTR) design procedure for linear multivariable feedback systems. LQR/LTR is interpreted as the solution of a specific weighted H-squared tradeoff between transfer functions in the frequency domain. Properties of this solution are examined for both minimum-phase and nonminimum-phase systems. This leads to a formal weight augmentation procedure for the minimum-phase case which permits essentially arbitrary specification of system sensitivity functions in terms of the weights. While such arbitrary specifications are not possible for nonminimum-phase problems, a direct relationship between weights and sensitivities is developed for nonminimum-phase SISO and certain nonminimum-phase MIMO cases which guides the weight selection process.

  5. Neural Net-Based Redesign of Transonic Turbines for Improved Unsteady Aerodynamic Performance

    NASA Technical Reports Server (NTRS)

    Madavan, Nateri K.; Rai, Man Mohan; Huber, Frank W.

    1998-01-01

    A recently developed neural net-based aerodynamic design procedure is used in the redesign of a transonic turbine stage to improve its unsteady aerodynamic performance. The redesign procedure used incorporates the advantages of both traditional response surface methodology (RSM) and neural networks by employing a strategy called parameter-based partitioning of the design space. Starting from the reference design, a sequence of response surfaces based on both neural networks and polynomial fits are constructed to traverse the design space in search of an optimal solution that exhibits improved unsteady performance. The procedure combines the power of neural networks and the economy of low-order polynomials (in terms of number of simulations required and network training requirements). A time-accurate, two-dimensional, Navier-Stokes solver is used to evaluate the various intermediate designs and provide inputs to the optimization procedure. The optimization procedure yields a modified design that improves the aerodynamic performance through small changes to the reference design geometry. The computed results demonstrate the capabilities of the neural net-based design procedure, and also show the tremendous advantages that can be gained by including high-fidelity unsteady simulations that capture the relevant flow physics in the design optimization process.

  6. Improving the Unsteady Aerodynamic Performance of Transonic Turbines using Neural Networks

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan; Madavan, Nateri K.; Huber, Frank W.

    1999-01-01

    A recently developed neural net-based aerodynamic design procedure is used in the redesign of a transonic turbine stage to improve its unsteady aerodynamic performance. The redesign procedure used incorporates the advantages of both traditional response surface methodology and neural networks by employing a strategy called parameter-based partitioning of the design space. Starting from the reference design, a sequence of response surfaces based on both neural networks and polynomial fits are constructed to traverse the design space in search of an optimal solution that exhibits improved unsteady performance. The procedure combines the power of neural networks and the economy of low-order polynomials (in terms of number of simulations required and network training requirements). A time-accurate, two-dimensional, Navier-Stokes solver is used to evaluate the various intermediate designs and provide inputs to the optimization procedure. The procedure yielded a modified design that improves the aerodynamic performance through small changes to the reference design geometry. These results demonstrate the capabilities of the neural net-based design procedure, and also show the advantages of including high-fidelity unsteady simulations that capture the relevant flow physics in the design optimization process.

  7. Revised MITG design, fabrication procedure, and performance predictions

    SciTech Connect

    Schock, A.

    1983-01-01

    The design, analysis, and key features of the Modular Isotopic Thermoelectric Generator (MITG) were described in a 1981 IECEC paper; and the design, fabrication, testing, and post-test analysis of test assemblies simulating prototypical MITG modules were described in preceding papers in these proceedings. These analyses succeeded in identifying and explaining the principal causes of thermal-stress problems encountered in the tests, and in confirming the effectiveness of design changes for alleviating them. The present paper presents additional design improvements for solving these and other problems, and describes new thermoelectric material properties generated by independent laboratories over the past two years. Based on these changes and on a revised fabrication procedure, it presents a reoptimization of the MITG design and computes the power-to-weight ratio for the revised design. That ratio is appreciably lower than the 1981 prediction, primarily because of changes in material properties; but it is still much higher than the specific power of current-generation RTGs.

  8. New technology in turbine aerodynamics.

    NASA Technical Reports Server (NTRS)

    Glassman, A. J.; Moffitt, T. P.

    1972-01-01

    Cursory review of some recent work that has been done in turbine aerodynamic research. Topics discussed include the aerodynamic effect of turbine coolant, high work-factor (ratio of stage work to square of blade speed) turbines, and computer methods for turbine design and performance prediction. Experimental cooled-turbine aerodynamics programs using two-dimensional cascades, full annular cascades, and cold rotating turbine stage tests are discussed with some typical results presented. Analytically predicted results for cooled blade performance are compared to experimental results. The problems and some of the current programs associated with the use of very high work factors for fan-drive turbines of high-bypass-ratio engines are discussed. Computer programs have been developed for turbine design-point performance, off-design performance, supersonic blade profile design, and the calculation of channel velocities for subsonic and transonic flowfields. The use of these programs for the design and analysis of axial and radial turbines is discussed.

  9. Computational aerodynamics and artificial intelligence

    NASA Technical Reports Server (NTRS)

    Kutler, P.; Mehta, U. B.

    1984-01-01

    Some aspects of artificial intelligence are considered and questions are speculated on, including how knowledge-based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use 'expert' systems and how expert systems may speed the design and development process. The anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements are examined for using artificial intelligence in computational fluid dynamics and aerodynamics. Considering two of the essentials of computational aerodynamics - reasoniing and calculating - it is believed that a substantial part of the reasoning can be achieved with artificial intelligence, with computers being used as reasoning machines to set the stage for calculating. Expert systems will probably be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  10. Computational aerodynamics and artificial intelligence

    NASA Technical Reports Server (NTRS)

    Mehta, U. B.; Kutler, P.

    1984-01-01

    The general principles of artificial intelligence are reviewed and speculations are made concerning how knowledge based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use expert systems, and how expert systems may speed the design and development process. In addition, the anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements for using artificial intelligence in computational fluid dynamics and aerodynamics are examined. Three main conclusions are presented. First, there are two related aspects of computational aerodynamics: reasoning and calculating. Second, a substantial portion of reasoning can be achieved with artificial intelligence. It offers the opportunity of using computers as reasoning machines to set the stage for efficient calculating. Third, expert systems are likely to be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  11. A design procedure for active control of beam vibrations

    NASA Technical Reports Server (NTRS)

    Dickerson, S. L.; Jarocki, G.

    1983-01-01

    The transverse vibrations of beams is discussed and a methodology for the design of an active damping device is given. The Bernoulli-Euler equation is used to derive a transcendental transfer function, which relates a torque applied at one end of the beam to the rotational position and velocity at that point. The active damping device consists of a wire, a linear actuator and a short torque arm attached to one end of the beam. The action of the actuator varies a tension in the wire and creates a torque which opposes the rotation of the beam and thus damps vibration. A design procedure for such an active damper is given. This procedure shows the relationships and trade-offs between the actuator stroke, power required, stress levels in the wire and beam and the geometry of the beam and wire. It is shown that by consideration of the frequency response at the beam natural frequencies, the aforementioned relationships can be greatly simplified. Similarly, a simple way of estimating the effective damping ratios and eigenvalue locations of actively controlled beams is presented.

  12. Aerodynamic characteristics of wings designed with a combined-theory method to cruise at a Mach number of 4.5

    NASA Technical Reports Server (NTRS)

    Mack, Robert J.

    1988-01-01

    A wind-tunnel study was conducted to determine the capability of a method combining linear theory and shock-expansion theory to design optimum camber surfaces for wings that will fly at high-supersonic/low-hypersonic speeds. Three force models (a flat-plate reference wing and two cambered and twisted wings) were used to obtain aerodynamic lift, drag, and pitching-moment data. A fourth pressure-orifice model was used to obtain surface-pressure data. All four wing models had the same planform, airfoil section, and centerbody area distribution. The design Mach number was 4.5, but data were also obtained at Mach numbers of 3.5 and 4.0. Results of these tests indicated that the use of airfoil thickness as a theoretical optimum, camber-surface design constraint did not improve the aerodynamic efficiency or performance of a wing as compared with a wing that was designed with a zero-thickness airfoil (linear-theory) constraint.

  13. Sensitivity analysis in computational aerodynamics

    NASA Technical Reports Server (NTRS)

    Bristow, D. R.

    1984-01-01

    Information on sensitivity analysis in computational aerodynamics is given in outline, graphical, and chart form. The prediction accuracy if the MCAERO program, a perturbation analysis method, is discussed. A procedure for calculating perturbation matrix, baseline wing paneling for perturbation analysis test cases and applications of an inviscid sensitivity matrix are among the topics covered.

  14. Aerodynamic performance and particle image velocimetery of piezo actuated biomimetic manduca sexta engineered wings towards the design and application of a flapping wing flight vehicle

    NASA Astrophysics Data System (ADS)

    DeLuca, Anthony M.

    Considerable research and investigation has been conducted on the aerodynamic performance, and the predominate flow physics of the Manduca Sexta size of biomimetically designed and fabricated wings as part of the AFIT FWMAV design project. Despite a burgeoning interest and research into the diverse field of flapping wing flight and biomimicry, the aerodynamics of flapping wing flight remains a nebulous field of science with considerable variance into the theoretical abstractions surrounding aerodynamic mechanisms responsible for aerial performance. Traditional FWMAV flight models assume a form of a quasi-steady approximation of wing aerodynamics based on an infinite wing blade element model (BEM). An accurate estimation of the lift, drag, and side force coefficients is a critical component of autonomous stability and control models. This research focused on two separate experimental avenues into the aerodynamics of AFIT's engineered hawkmoth wings|forces and flow visualization. 1. Six degree of freedom force balance testing, and high speed video analysis was conducted on 30°, 45°, and 60° angle stop wings. A novel, non-intrusive optical tracking algorithm was developed utilizing a combination of a Gaussian Mixture Model (GMM) and ComputerVision (OpenCV) tools to track the wing in motion from multiple cameras. A complete mapping of the wing's kinematic angles as a function of driving amplitude was performed. The stroke angle, elevation angle, and angle of attack were tabulated for all three wings at driving amplitudes ranging from A=0.3 to A=0.6. The wing kinematics together with the force balance data was used to develop several aerodynamic force coefficient models. A combined translational and rotational aerodynamic model predicted lift forces within 10%, and vertical forces within 6%. The total power consumption was calculated for each of the three wings, and a Figure of Merit was calculated for each wing as a general expression of the overall efficiency of

  15. A design procedure and handling quality criteria for lateral directional flight control systems

    NASA Technical Reports Server (NTRS)

    Stein, G.; Henke, A. H.

    1972-01-01

    A practical design procedure for aircraft augmentation systems is described based on quadratic optimal control technology and handling-quality-oriented cost functionals. The procedure is applied to the design of a lateral-directional control system for the F4C aircraft. The design criteria, design procedure, and final control system are validated with a program of formal pilot evaluation experiments.

  16. A program to compute three-dimensional subsonic unsteady aerodynamic characteristics using the doublet lattice method, L216 (DUBFLEX). Volume 2: Supplemental system design and maintenance document

    NASA Technical Reports Server (NTRS)

    Harrison, B. A.; Richard, M.

    1979-01-01

    The information necessary for execution of the digital computer program L216 on the CDC 6600 is described. L216 characteristics are based on the doublet lattice method. Arbitrary aerodynamic configurations may be represented with combinations of nonplanar lifting surfaces composed of finite constant pressure panel elements, and axially summetric slender bodies composed of constant pressure line elements. Program input consists of configuration geometry, aerodynamic parameters, and modal data; output includes element geometry, pressure difference distributions, integrated aerodynamic coefficients, stability derivatives, generalized aerodynamic forces, and aerodynamic influence coefficient matrices. Optionally, modal data may be input on magnetic field (tape or disk), and certain geometric and aerodynamic output may be saved for subsequent use.

  17. Collaborative Behavioral Teratology Study: protocol design and testing procedures.

    PubMed

    Adams, J; Buelke-Sam, J; Kimmel, C A; Nelson, C J; Reiter, L W; Sobotka, T J; Tilson, H A; Nelson, B K

    1985-01-01

    This paper presents background information on the methods used in the Collaborative Behavioral Teratology Study (CBTS), the rationale behind the experimental design, and the design and specific procedures used in the CBTS. Each of the following methods is discussed: negative geotaxis, olfactory discrimination, auditory startle habituation, one-hour activity in the figure-8 maze, visual discrimination learning, 23-hour activity in the figure-8 maze, and amphetamine-stimulated activity. The CBTS was designed to determine the intra- and interlaboratory reliability of these test methods and the detection sensitivity of each method, as well as to determine the importance of several major variables (early test experience, gender, litter). The important design features which permitted these evaluations are discussed. Each laboratory conducted two independent experiments: one using d-amphetamine sulfate as the test agent and one using methylmercuric chloride. Other than the use of different agents and dosing regimens in the two studies, all other characteristics of experimental design were identical. Each study was conducted in four replicates with 4 litters/each of 4 treatment groups/replicate. The replicate design was an important feature which permitted reliability of the tests to be addressed under conditions in which several other sources of variation in responding could be identified and accounted for in the model. Other methods by which optimal testing conditions were implemented in the participating laboratories included the "blind" testing of all subjects in specific orders which were counterbalanced for treatment group, time of day, and the apparatus in which the animals were placed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3835452

  18. Recent advances in computational aerodynamics

    NASA Astrophysics Data System (ADS)

    Agarwal, Ramesh K.; Desse, Jerry E.

    1991-04-01

    The current state of the art in computational aerodynamics is described. Recent advances in the discretization of surface geometry, grid generation, and flow simulation algorithms have led to flowfield predictions for increasingly complex and realistic configurations. As a result, computational aerodynamics is emerging as a crucial enabling technology for the development and design of flight vehicles. Examples illustrating the current capability for the prediction of aircraft, launch vehicle and helicopter flowfields are presented. Unfortunately, accurate modeling of turbulence remains a major difficulty in the analysis of viscosity-dominated flows. In the future inverse design methods, multidisciplinary design optimization methods, artificial intelligence technology and massively parallel computer technology will be incorporated into computational aerodynamics, opening up greater opportunities for improved product design at substantially reduced costs.

  19. Computational procedures for optimal experimental design in biological systems.

    PubMed

    Balsa-Canto, E; Alonso, A A; Banga, J R

    2008-07-01

    Mathematical models of complex biological systems, such as metabolic or cell-signalling pathways, usually consist of sets of nonlinear ordinary differential equations which depend on several non-measurable parameters that can be hopefully estimated by fitting the model to experimental data. However, the success of this fitting is largely conditioned by the quantity and quality of data. Optimal experimental design (OED) aims to design the scheme of actuations and measurements which will result in data sets with the maximum amount and/or quality of information for the subsequent model calibration. New methods and computational procedures for OED in the context of biological systems are presented. The OED problem is formulated as a general dynamic optimisation problem where the time-dependent stimuli profiles, the location of sampling times, the duration of the experiments and the initial conditions are regarded as design variables. Its solution is approached using the control vector parameterisation method. Since the resultant nonlinear optimisation problem is in most of the cases non-convex, the use of a robust global nonlinear programming solver is proposed. For the sake of comparing among different experimental schemes, a Monte-Carlo-based identifiability analysis is then suggested. The applicability and advantages of the proposed techniques are illustrated by considering an example related to a cell-signalling pathway. PMID:18681746

  20. New procedures of ergonomics design in a large oil company.

    PubMed

    Alhadeff, Cynthia Mossé; Silva, Rosana Fernandes da; Reis, Márcia Sales dos

    2012-01-01

    This study presents the challenge involved in the negotiation and construction of a standard process in a major petroleum company that has the purpose of guiding the implementation of ergonomic studies in the development of projects, systemising the implementation of ergonomics design. The standard was created by a multi-disciplinary working group consisting of specialists in ergonomics, who work in a number of different areas of the company. The objective was to guide "how to" undertake ergonomics in all projects, taking into consideration the development of the ergonomic appraisals of work. It also established that all the process, in each project phase, should be accompanied by a specialist in ergonomics. This process as an innovation in the conception of projects in this company, signals a change of culture, and, for this reason requires broad dissemination throughout the several company leadership levels, and training of professionals in projects of ergonomics design. An implementation plan was also prepared and approved by the corporate governance, complementing the proposed challenge. In this way, this major oil company will implement new procedures of ergonomics design to promote health, safety, and wellbeing of the workforce, besides improving the performance and reliability of its systems and processes. PMID:22316810

  1. Index for aerodynamic data from the Bumblebee program

    NASA Technical Reports Server (NTRS)

    Cronvich, L. L.; Barnes, G. A.

    1978-01-01

    The Bumblebee program, was designed to provide a supersonic guided missile. The aerodynamics program included a fundamental research effort in supersonic aerodynamics as well as a design task in developing both test vehicles and prototypes of tactical missiles. An index of aerodynamic missile data developed in this program is presented.

  2. Grid Sensitivity and Aerodynamic Optimization of Generic Airfoils

    NASA Technical Reports Server (NTRS)

    Sadrehaghighi, Ideen; Smith, Robert E.; Tiwari, Surendra N.

    1995-01-01

    An algorithm is developed to obtain the grid sensitivity with respect to design parameters for aerodynamic optimization. The procedure is advocating a novel (geometrical) parameterization using spline functions such as NURBS (Non-Uniform Rational B- Splines) for defining the airfoil geometry. An interactive algebraic grid generation technique is employed to generate C-type grids around airfoils. The grid sensitivity of the domain with respect to geometric design parameters has been obtained by direct differentiation of the grid equations. A hybrid approach is proposed for more geometrically complex configurations such as a wing or fuselage. The aerodynamic sensitivity coefficients are obtained by direct differentiation of the compressible two-dimensional thin-layer Navier-Stokes equations. An optimization package has been introduced into the algorithm in order to optimize the airfoil surface. Results demonstrate a substantially improved design due to maximized lift/drag ratio of the airfoil.

  3. Integration of dynamic, aerodynamic, and structural optimization of helicopter rotor blades

    NASA Technical Reports Server (NTRS)

    Peters, David A.

    1991-01-01

    Summarized here is the first six years of research into the integration of structural, dynamic, and aerodynamic considerations in the design-optimization process for rotor blades. Specifically discussed here is the application of design optimization techniques for helicopter rotor blades. The reduction of vibratory shears and moments at the blade root, aeroelastic stability of the rotor, optimum airframe design, and an efficient procedure for calculating system sensitivities with respect to the design variables used are discussed.

  4. 48 CFR 570.305 - Two-phase design-build selection procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by...

  5. 48 CFR 570.305 - Two-phase design-build selection procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by...

  6. 48 CFR 570.305 - Two-phase design-build selection procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by...

  7. 48 CFR 570.305 - Two-phase design-build selection procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by...

  8. Fast-Running Aeroelastic Code Based on Unsteady Linearized Aerodynamic Solver Developed

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.; Bakhle, Milind A.; Keith, T., Jr.

    2003-01-01

    The NASA Glenn Research Center has been developing aeroelastic analyses for turbomachines for use by NASA and industry. An aeroelastic analysis consists of a structural dynamic model, an unsteady aerodynamic model, and a procedure to couple the two models. The structural models are well developed. Hence, most of the development for the aeroelastic analysis of turbomachines has involved adapting and using unsteady aerodynamic models. Two methods are used in developing unsteady aerodynamic analysis procedures for the flutter and forced response of turbomachines: (1) the time domain method and (2) the frequency domain method. Codes based on time domain methods require considerable computational time and, hence, cannot be used during the design process. Frequency domain methods eliminate the time dependence by assuming harmonic motion and, hence, require less computational time. Early frequency domain analyses methods neglected the important physics of steady loading on the analyses for simplicity. A fast-running unsteady aerodynamic code, LINFLUX, which includes steady loading and is based on the frequency domain method, has been modified for flutter and response calculations. LINFLUX, solves unsteady linearized Euler equations for calculating the unsteady aerodynamic forces on the blades, starting from a steady nonlinear aerodynamic solution. First, we obtained a steady aerodynamic solution for a given flow condition using the nonlinear unsteady aerodynamic code TURBO. A blade vibration analysis was done to determine the frequencies and mode shapes of the vibrating blades, and an interface code was used to convert the steady aerodynamic solution to a form required by LINFLUX. A preprocessor was used to interpolate the mode shapes from the structural dynamic mesh onto the computational dynamics mesh. Then, we used LINFLUX to calculate the unsteady aerodynamic forces for a given mode, frequency, and phase angle. A postprocessor read these unsteady pressures and

  9. Damage tolerance design procedures for an automotive composite

    SciTech Connect

    Corum, J.M.; Battiste, R.L.

    1998-11-01

    Among the durability issues of concern in the use of composites in automobile structures is the damaging effects that low-energy impacts (e.g., tool drops and roadway kickups) might have on strength and stiffness. This issue was experimentally investigated, and recommended design evaluation procedures were developed for a candidate automotive structural composite--a structural reaction injection-molded polyurethane reinforced with continuous strand, swirl-mat E-glass fibers. Two test facilities were built to cover the range of impacts of interest--a pendulum device to characterize the effects of relative heavy objects at low velocities and an air gun to characterize the effects of relatively light objects at higher velocities. In all cases, the test specimen was a 9 x 9 x 1/8-in.-thick plate clamped on an 8-in.-diam circle. Sixty-five impact tests were performed. Included were tests using various impactor sizes and weights, tests at {minus}40 F, and tests on specimens that has been presoaked in water or exposed to battery acid. Damage areas were determined using ultrasonic C-scans, and the resulting areas were found to correlate with the quantity impactor mass to a power times velocity. A design curve was derived from the correlation and validated using dropped brick tests. To evaluate strength and stiffness reductions, the impacted plate specimens were cut into tensile, compressive, and fatigue test specimens that were used to determine reductions as a function of damage area. It was found that for design purposes, the strength reduction could be determined by representing the damage area by a circular hole of equivalent area.

  10. Evaluation of vertical profiles to design continuous descent approach procedure

    NASA Astrophysics Data System (ADS)

    Pradeep, Priyank

    The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft and Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of the air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data (BADA) of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK, EWR and LGA)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of

  11. New technology in turbine aerodynamics

    NASA Technical Reports Server (NTRS)

    Glassman, A. J.; Moffitt, T. P.

    1972-01-01

    A cursory review is presented of some of the recent work that has been done in turbine aerodynamic research at NASA-Lewis Research Center. Topics discussed include the aerodynamic effect of turbine coolant, high work-factor (ratio of stage work to square of blade speed) turbines, and computer methods for turbine design and performance prediction. An extensive bibliography is included. Experimental cooled-turbine aerodynamics programs using two-dimensional cascades, full annular cascades, and cold rotating turbine stage tests are discussed with some typical results presented. Analytically predicted results for cooled blade performance are compared to experimental results. The problems and some of the current programs associated with the use of very high work factors for fan-drive turbines of high-bypass-ratio engines are discussed. Turbines currently being investigated make use of advanced blading concepts designed to maintain high efficiency under conditions of high aerodynamic loading. Computer programs have been developed for turbine design-point performance, off-design performance, supersonic blade profile design, and the calculation of channel velocities for subsonic and transonic flow fields. The use of these programs for the design and analysis of axial and radial turbines is discussed.

  12. Numerical Aerodynamic Simulation (NAS)

    NASA Technical Reports Server (NTRS)

    Peterson, V. L.; Ballhaus, W. F., Jr.; Bailey, F. R.

    1983-01-01

    The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified.

  13. Aerodynamic design and analysis of the AST-204, AST-205, and AST-206 blended wing-fuse large supersonic transport configuration concepts

    NASA Technical Reports Server (NTRS)

    Martin, G. L.; Walkley, K. B.

    1980-01-01

    The aerodynamic design and analysis of three blended wing-fuselage supersonic cruise configurations providing four, five, and six abreast seating was conducted using a previously designed supersonic cruise configuration as the baseline. The five abreast configuration was optimized for wave drag at a Mach number of 2.7. The four and six abreast configurations were also optimized at Mach 2.7, but with the added constraint that the majority of their structure be common with the five abreast configuration. Analysis of the three configurations indicated an improvement of 6.0, 7.5, and 7.7 percent in cruise lift-to-drag ratio over the baseline configuration for the four, five, and six abreast configurations, respectively.

  14. Fully integrated aerodynamic/dynamic optimization of helicopter rotor blades

    NASA Technical Reports Server (NTRS)

    Walsh, Joanne L.; Lamarsh, William J., II; Adelman, Howard M.

    1992-01-01

    A fully integrated aerodynamic/dynamic optimization procedure is described for helicopter rotor blades. The procedure combines performance and dynamic analyses with a general purpose optimizer. The procedure minimizes a linear combination of power required (in hover, forward flight, and maneuver) and vibratory hub shear. The design variables include pretwist, taper initiation, taper ratio, root chord, blade stiffnesses, tuning masses, and tuning mass locations. Aerodynamic constraints consist of limits on power required in hover, forward flight and maneuvers; airfoil section stall; drag divergence Mach number; minimum tip chord; and trim. Dynamic constraints are on frequencies, minimum autorotational inertia, and maximum blade weight. The procedure is demonstrated for two cases. In the first case, the objective function involves power required (in hover, forward flight and maneuver) and dynamics. The second case involves only hover power and dynamics. The designs from the integrated procedure are compared with designs from a sequential optimization approach in which the blade is first optimized for performance and then for dynamics. In both cases, the integrated approach is superior.

  15. Model of Procedure Usage – Results from a Qualitative Study to Inform Design of Computer-Based Procedures

    SciTech Connect

    Johanna H Oxstrand; Katya L Le Blanc

    2012-07-01

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory, the Institute for Energy Technology, and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field operators. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do this. The underlying philosophy in the research effort is “Stop – Start – Continue”, i.e. what features from the use of paper-based procedures should we not incorporate (Stop), what should we keep (Continue), and what new features or work processes should be added (Start). One step in identifying the Stop – Start – Continue was to conduct a baseline study where affordances related to the current usage of paper-based procedures were identified. The purpose of the study was to develop a model of paper based procedure use which will help to identify desirable features for computer based procedure prototypes. Affordances such as note taking, markups

  16. 46 CFR 3.10-1 - Procedures for designating oceanographic research vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Procedures for designating oceanographic research... TO THE PUBLIC DESIGNATION OF OCEANOGRAPHIC RESEARCH VESSELS Designation § 3.10-1 Procedures for designating oceanographic research vessels. (a) Upon written request by the owner, master, or agent of...

  17. Sensitivity Analysis and Optimization of Aerodynamic Configurations with Blend Surfaces

    NASA Technical Reports Server (NTRS)

    Thomas, A. M.; Tiwari, S. N.

    1997-01-01

    A novel (geometrical) parametrization procedure using solutions to a suitably chosen fourth order partial differential equation is used to define a class of airplane configurations. Inclusive in this definition are surface grids, volume grids, and grid sensitivity. The general airplane configuration has wing, fuselage, vertical tail and horizontal tail. The design variables are incorporated into the boundary conditions, and the solution is expressed as a Fourier series. The fuselage has circular cross section, and the radius is an algebraic function of four design parameters and an independent computational variable. Volume grids are obtained through an application of the Control Point Form method. A graphic interface software is developed which dynamically changes the surface of the airplane configuration with the change in input design variable. The software is made user friendly and is targeted towards the initial conceptual development of any aerodynamic configurations. Grid sensitivity with respect to surface design parameters and aerodynamic sensitivity coefficients based on potential flow is obtained using an Automatic Differentiation precompiler software tool ADIFOR. Aerodynamic shape optimization of the complete aircraft with twenty four design variables is performed. Unstructured and structured volume grids and Euler solutions are obtained with standard software to demonstrate the feasibility of the new surface definition.

  18. 40 CFR 240.203-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures..., variations in waste generation, equipment downtime, and availability of alternate storage, processing,...

  19. Classical Aerodynamic Theory

    NASA Technical Reports Server (NTRS)

    Jones, R. T. (Compiler)

    1979-01-01

    A collection of papers on modern theoretical aerodynamics is presented. Included are theories of incompressible potential flow and research on the aerodynamic forces on wing and wing sections of aircraft and on airship hulls.

  20. 22 CFR 142.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... adoption of grievance procedures. 142.7 Section 142.7 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS... Provisions § 142.7 Designation of responsible employee and adoption of grievance procedures. (a) Designation... person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  1. 24 CFR 8.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and adoption of grievance procedures. 8.53 Section 8.53 Housing and Urban Development Office of the... Designation of responsible employee and adoption of grievance procedures. (a) Designation of responsible... coordinate its efforts to comply with this part. (b) Adoption of grievance procedures. A recipient...

  2. 22 CFR 142.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... adoption of grievance procedures. 142.7 Section 142.7 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS... Provisions § 142.7 Designation of responsible employee and adoption of grievance procedures. (a) Designation... person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  3. 22 CFR 142.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... adoption of grievance procedures. 142.7 Section 142.7 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS... Provisions § 142.7 Designation of responsible employee and adoption of grievance procedures. (a) Designation... person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  4. 24 CFR 8.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... and adoption of grievance procedures. 8.53 Section 8.53 Housing and Urban Development Office of the... Designation of responsible employee and adoption of grievance procedures. (a) Designation of responsible... coordinate its efforts to comply with this part. (b) Adoption of grievance procedures. A recipient...

  5. 22 CFR 142.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... adoption of grievance procedures. 142.7 Section 142.7 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS... Provisions § 142.7 Designation of responsible employee and adoption of grievance procedures. (a) Designation... person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  6. 24 CFR 8.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... and adoption of grievance procedures. 8.53 Section 8.53 Housing and Urban Development Office of the... Designation of responsible employee and adoption of grievance procedures. (a) Designation of responsible... coordinate its efforts to comply with this part. (b) Adoption of grievance procedures. A recipient...

  7. 24 CFR 8.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... and adoption of grievance procedures. 8.53 Section 8.53 Housing and Urban Development Office of the... Designation of responsible employee and adoption of grievance procedures. (a) Designation of responsible... coordinate its efforts to comply with this part. (b) Adoption of grievance procedures. A recipient...

  8. 23 CFR 636.202 - When are two-phase design-build selection procedures appropriate?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false When are two-phase design-build selection procedures... When are two-phase design-build selection procedures appropriate? You may consider the following criteria in deciding whether two-phase selection procedures are appropriate. A negative response...

  9. NASA aerodynamics program

    NASA Technical Reports Server (NTRS)

    Williams, Louis J.; Hessenius, Kristin A.; Corsiglia, Victor R.; Hicks, Gary; Richardson, Pamela F.; Unger, George; Neumann, Benjamin; Moss, Jim

    1992-01-01

    The annual accomplishments is reviewed for the Aerodynamics Division during FY 1991. The program includes both fundamental and applied research directed at the full spectrum of aerospace vehicles, from rotorcraft to planetary entry probes. A comprehensive review is presented of the following aerodynamics elements: computational methods and applications; CFD validation; transition and turbulence physics; numerical aerodynamic simulation; test techniques and instrumentation; configuration aerodynamics; aeroacoustics; aerothermodynamics; hypersonics; subsonics; fighter/attack aircraft and rotorcraft.

  10. Configuration Aerodynamics: Past - Present - Future

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Agrawal, Shreekant; Bencze, Daniel P.; Kulfan, Robert M.; Wilson, Douglas L.

    1999-01-01

    The Configuration Aerodynamics (CA) element of the High Speed Research (HSR) program is managed by a joint NASA and Industry team, referred to as the Technology Integration Development (ITD) team. This team is responsible for the development of a broad range of technologies for improved aerodynamic performance and stability and control characteristics at subsonic to supersonic flight conditions. These objectives are pursued through the aggressive use of advanced experimental test techniques and state of the art computational methods. As the HSR program matures and transitions into the next phase the objectives of the Configuration Aerodynamics ITD are being refined to address the drag reduction needs and stability and control requirements of High Speed Civil Transport (HSCT) aircraft. In addition, the experimental and computational tools are being refined and improved to meet these challenges. The presentation will review the work performed within the Configuration Aerodynamics element in 1994 and 1995 and then discuss the plans for the 1996-1998 time period. The final portion of the presentation will review several observations of the HSR program and the design activity within Configuration Aerodynamics.

  11. 17 CFR 38.3 - Procedures for designation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... description of the trading system, algorithm, security and access limitation procedures with a timeline for an order from input through settlement, and a copy of any system test procedures, tests conducted, test....3 Section 38.3 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION...

  12. 17 CFR 38.3 - Procedures for designation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... description of the trading system, algorithm, security and access limitation procedures with a timeline for an order from input through settlement, and a copy of any system test procedures, tests conducted, test....3 Section 38.3 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION...

  13. NASA aerodynamics program

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.; Schairer, Edward; Hicks, Gary; Wander, Stephen; Blankson, Isiaiah; Rose, Raymond; Olson, Lawrence; Unger, George

    1990-01-01

    Presented here is a comprehensive review of the following aerodynamics elements: computational methods and applications, computational fluid dynamics (CFD) validation, transition and turbulence physics, numerical aerodynamic simulation, drag reduction, test techniques and instrumentation, configuration aerodynamics, aeroacoustics, aerothermodynamics, hypersonics, subsonic transport/commuter aviation, fighter/attack aircraft and rotorcraft.

  14. Application of two procedures for dual-point design of transonic airfoils

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.; Campbell, Richard L.; Allison, Dennis O.

    1994-01-01

    Two dual-point design procedures were developed to reduce the objective function of a baseline airfoil at two design points. The first procedure to develop a redesigned airfoil used a weighted average of the shapes of two intermediate airfoils redesigned at each of the two design points. The second procedure used a weighted average of two pressure distributions obtained from an intermediate airfoil redesigned at each of the two design points. Each procedure was used to design a new airfoil with reduced wave drag at the cruise condition without increasing the wave drag or pitching moment at the climb condition. Two cycles of the airfoil shape-averaging procedure successfully designed a new airfoil that reduced the objective function and satisfied the constraints. One cycle of the target (desired) pressure-averaging procedure was used to design two new airfoils that reduced the objective function and came close to satisfying the constraints.

  15. Freight Wing Trailer Aerodynamics

    SciTech Connect

    Graham, Sean; Bigatel, Patrick

    2004-10-17

    Freight Wing Incorporated utilized the opportunity presented by this DOE category one Inventions and Innovations grant to successfully research, develop, test, patent, market, and sell innovative fuel and emissions saving aerodynamic attachments for the trucking industry. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck's fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Market research early in this project revealed the demands of truck fleet operators regarding aerodynamic attachments. Products must not only save fuel, but cannot interfere with the operation of the truck, require significant maintenance, add significant weight, and must be extremely durable. Furthermore, SAE/TMC J1321 tests performed by a respected independent laboratory are necessary for large fleets to even consider purchase. Freight Wing used this information to create a system of three practical aerodynamic attachments for the front, rear and undercarriage of standard semi trailers. SAE/TMC J1321 Type II tests preformed by the Transportation Research Center (TRC) demonstrated a 7% improvement to fuel economy with all three products. If Freight Wing is successful in its continued efforts to gain market penetration, the energy and environmental savings would be considerable. Each truck outfitted saves approximately 1,100 gallons of fuel every 100,000 miles, which prevents over 12 tons of CO2 from entering the atmosphere. If all applicable trailers used the technology, the country could save approximately 1.8 billion gallons of diesel fuel, 18 million tons of emissions and 3.6 billion dollars annually.

  16. Interdisciplinary optimization combining electromagnetic and aerodynamic methods

    NASA Astrophysics Data System (ADS)

    Sullivan, Anders James

    The design of missile body shapes often requires a compromise between aero-dynamic and electromagnetic performance goals. In general, the missile shape producing the lowest radar signature will be different from the preferred aero-dynamic shape. Interdisciplinary shape optimization is utilized to combine multiple disciplines to determine the best possible shape for a hybrid aerodynamic-electromagnetic problem. A composite missile body consisting of an axisymmetric body of revolution (BOR) and two thin flat plate attachments is considered. The goal is to minimize the drag and backscatter associated with this composite shape. The body is assumed to be perfectly conducting, and flying at zero degrees angle of attack. The variable nose shape serves as the optimization design parameter. To characterize the system performance, a cost function is defined which is comprised of weighted values of the drag and backscatter. To solve the electromagnetic problem, methods to treat electrically large complex bodies are investigated. Hybrid methods which combine the method of moments (MoM) with physical optics (PO) are developed to calculate the scattering from simple two-dimensional bodies. A surface-wave hybrid approach is shown to effectively approximate the traveling wave currents on the smooth interior portions of a BOR. Asymptotic methods are used to solve the resulting integral equations more efficiently. The hybrid methods are shown to produce MoM-quality results, while requiring less computational resources. To solve the composite body problem, an iterative technique is developed that preserves the simplicity of the original BOR scheme. In this formulation, the current over each part of the composite body is solved independently. The results from one part of the body are used to update the fields incident on the other part of the body. This procedure is repeated until the solution converges. To solve the aerodynamic problem, slender body theory is used to calculate the

  17. Aerodynamic detuning analysis of an unstalled supersonic turbofan cascade

    NASA Technical Reports Server (NTRS)

    Hoyniak, D.; Fleeter, S.

    1985-01-01

    An approach to passive flutter control is aerodynamic detuning, defined as designed passage-to-passage differences in the unsteady aerodynamic flow field of a rotor blade row. Thus, aerodynamic detuning directly affects the fundamental driving mechanism for flutter. A model to demonstrate the enhanced supersonic aeroelastic stability associated with aerodynamic detuning is developed. The stability of an aerodynamically detuned cascade operating in a supersonic inlet flow field with a subsonic leading edge locus is analyzed, with the aerodynamic detuning accomplished by means of nonuniform circumferential spacing of adjacent rotor blades. The unsteady aerodynamic forces and moments on the blading are defined in terms of influence coefficients in a manner that permits the stability of both a conventional uniformally spaced rotor configuration as well as the detuned nonuniform circumferentially spaced rotor to be determined. With Verdon's uniformly spaced Cascade B as a baseline, this analysis is then utilized to demonstrate the potential enhanced aeroelastic stability associated with this particular type of aerodynamic detuning.

  18. 40 CFR 240.209-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures...) Methods and/or equipment for removal of an injured person from the storage pit should be available....

  19. 1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executive summaries for all the Aerodynamic Performance technology areas.

  20. 36 CFR 1211.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Designation of responsible employee and adoption of grievance procedures. 1211.135 Section 1211.135 Parks, Forests, and Public... Designation of responsible employee and adoption of grievance procedures. (a) Designation of...

  1. 7 CFR 15a.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Designation of responsible employee and adoption of grievance procedures. 15a.7 Section 15a.7 Agriculture Office of the Secretary of Agriculture EDUCATION... Designation of responsible employee and adoption of grievance procedures. (a) Designation of...

  2. 44 CFR 19.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Designation of responsible employee and adoption of grievance procedures. 19.135 Section 19.135 Emergency Management and Assistance... § 19.135 Designation of responsible employee and adoption of grievance procedures. (a) Designation...

  3. 45 CFR 2555.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Designation of responsible employee and adoption of grievance procedures. 2555.135 Section 2555.135 Public Welfare Regulations Relating to Public... Designation of responsible employee and adoption of grievance procedures. (a) Designation of...

  4. 49 CFR 27.13 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Designation of responsible employee and adoption... General § 27.13 Designation of responsible employee and adoption of grievance procedures. (a) Designation... subsequent change. (b) Adoption of complaint procedures. A recipient that employs fifteen or more...

  5. 10 CFR 5.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Designation of responsible employee and adoption of grievance procedures. 5.135 Section 5.135 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE....135 Designation of responsible employee and adoption of grievance procedures. (a) Designation...

  6. 36 CFR 1211.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Designation of responsible employee and adoption of grievance procedures. 1211.135 Section 1211.135 Parks, Forests, and Public... Designation of responsible employee and adoption of grievance procedures. (a) Designation of...

  7. 7 CFR 15b.6 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Designation of responsible employee and adoption of... Provisions § 15b.6 Designation of responsible employee and adoption of grievance procedures. (a) Designation... one person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  8. 10 CFR 5.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Designation of responsible employee and adoption of grievance procedures. 5.135 Section 5.135 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE....135 Designation of responsible employee and adoption of grievance procedures. (a) Designation...

  9. 7 CFR 15a.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Designation of responsible employee and adoption of grievance procedures. 15a.7 Section 15a.7 Agriculture Office of the Secretary of Agriculture EDUCATION... Designation of responsible employee and adoption of grievance procedures. (a) Designation of...

  10. 7 CFR 15b.6 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Designation of responsible employee and adoption of... Provisions § 15b.6 Designation of responsible employee and adoption of grievance procedures. (a) Designation... one person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  11. 48 CFR 36.301 - Use of two-phase design-build selection procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Use of two-phase design... ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Two-Phase Design-Build Selection Procedures 36.301 Use of two-phase design-build selection procedures....

  12. 23 CFR 636.202 - When are two-phase design-build selection procedures appropriate?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Selection Procedures, Award Criteria § 636.202 When are two-phase design-build selection procedures appropriate? You may consider the following... 23 Highways 1 2011-04-01 2011-04-01 false When are two-phase design-build selection...

  13. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  14. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  15. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  16. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  17. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  18. Low Reynolds Number Aerodynamic Characteristics of Several Airplane Configurations Designed to Fly in the Mars Atmosphere at Subsonic Speeds

    NASA Technical Reports Server (NTRS)

    Re, Richard J.; Pendergraft, Odis C., Jr.; Campbell, Richard L.

    2006-01-01

    A 1/4-scale wind tunnel model of an airplane configuration developed for short duration flight at subsonic speeds in the Martian atmosphere has been tested in the Langley Research Center Transonic Dynamics Tunnel. The tunnel was pumped down to extremely low pressures to represent Martian Mach/Reynolds number conditions. Aerodynamic data were obtained and upper and lower surface wind pressures were measured at one spanwise station on some configurations. Three unswept wings of the same planform but different airfoil sections were tested. Horizontal tail incidence was varied as was the deflection of plain and split trailing-edge flaps. One unswept wing configuration was tested with the lower part of the fuselage removed and the vertical/horizontal tail assembly inverted and mounted from beneath the fuselage. A sweptback wing was also tested. Tests were conducted at Mach numbers from 0.50 to 0.90. Wing chord Reynolds number was varied from 40,000 to 100,000 and angles of attack and sideslip were varied from -10deg to 20deg and -10deg to 10deg, respectively.

  19. Design Reconstitution Program Plan and procedures for K Basins

    SciTech Connect

    Laney, T.

    1995-01-12

    This document establishes a systematic program to establish, organize, and document the design basis and design requirement information for the K Basins where existing design information is inadequate. The Design Reconstitution Program involves identifying and retrieving design information from identified source documents; evaluating, verifying, and validating the design information; resolving discrepancies; regenerating missing critical design information; and preparing and issuing a summary document of the design information. Upon completion, the design requirements shall be evaluated with the facility as-found configuration to verify the adequacy of appropriate design requirements with the as-found configuration and to document and resolve any discovered discrepancies. Once the design requirement (design analysis, calculation, design basis) comparison is made and discrepancies resolved (dispositioned, implemented, and incorporated as required), the as-found condition of a drawing then becomes an as-built drawing that is released into the engineering release system. This as-built drawing is then the accurate accounting of the field configuration that is consistent with the design requirements (recovered through the design reconstitution program) and is used with high confidence to make valid engineering, operational, and maintenance decisions.

  20. Aerodynamics and performance testing of the VAWT

    SciTech Connect

    Klimas, P.C.

    1981-01-01

    Early investigations suggest that reductions in cost of energy (COE) and increases in reliability for VAWT systems may be brought about through relatively inexpensive changes to the current aerodynamic design. This design uses blades of symmetrical cross-section mounted such that the radius from the rotating tower centerline is normal to the blade chord at roughly the 40% chord point. The envisioned changes to this existing design are intended to: (1) lower cut-in windspeed; (2) increase maximum efficiency; (3) limit maximum aerodynamic power; and (4) limit peak aerodynamic torques. This paper describes certain experiments designed to both better understand the aerodynamics of a section operating in an unsteady, curvilinear flowfield and achieve some of the desired changes in section properties. The common goal of all of these experiments is to lower VAWT COE and increase system reliability.

  1. Distributed Aerodynamic Sensing and Processing Toolbox

    NASA Technical Reports Server (NTRS)

    Brenner, Martin; Jutte, Christine; Mangalam, Arun

    2011-01-01

    A Distributed Aerodynamic Sensing and Processing (DASP) toolbox was designed and fabricated for flight test applications with an Aerostructures Test Wing (ATW) mounted under the fuselage of an F-15B on the Flight Test Fixture (FTF). DASP monitors and processes the aerodynamics with the structural dynamics using nonintrusive, surface-mounted, hot-film sensing. This aerodynamic measurement tool benefits programs devoted to static/dynamic load alleviation, body freedom flutter suppression, buffet control, improvement of aerodynamic efficiency through cruise control, supersonic wave drag reduction through shock control, etc. This DASP toolbox measures local and global unsteady aerodynamic load distribution with distributed sensing. It determines correlation between aerodynamic observables (aero forces) and structural dynamics, and allows control authority increase through aeroelastic shaping and active flow control. It offers improvements in flutter suppression and, in particular, body freedom flutter suppression, as well as aerodynamic performance of wings for increased range/endurance of manned/ unmanned flight vehicles. Other improvements include inlet performance with closed-loop active flow control, and development and validation of advanced analytical and computational tools for unsteady aerodynamics.

  2. Design procedures for fiber composite structural components: Panels subjected to combined in-plane loads

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1985-01-01

    Step by step procedures are described which can be used to design panels made from fiber composite angleplied laminates and subjected to combined in plane loads. The procedures are set up as a multistep sample design. Steps in the sample design procedure range from selection of the laminate configuration to the subsequent analyses required to check design requirements for: (1) displacement, (2) ply stresses, and (3) buckling. The sample design steps are supplemented with appropriate tabular and graphical data which can be used to expedite the design process.

  3. 7 CFR 1948.67 - Procedure for designation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Governor will define the geographic area of a designated area consistent with the nature of the impact and the socio-economic integration of the area. (c) The Governor may designate an area as an...

  4. Golf Aerodynamics

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A former Martin Marietta Manned Space Systems engineer, Robert T. Thurman went from analyzing airloads on the Space Shuttle External Tank to analyzing airloads on golf balls for Wilson Sporting Goods Company. Using his NASA know-how, Thurman designed the Ultra 500 golf ball, which has three different-sized dimples in 60 triangular faces (instead of the usual 20) formed by a series of intersecting "parting" lines. This balances the asymmetry caused by the molding line in all golf balls. According to Wilson, the ball sustains initial velocity longer and produces the most stable ball flight for "unmatched" accuracy and distance.

  5. 15 CFR 8b.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and adoption of grievance procedures. 8b.7 Section 8b.7 Commerce and Foreign Trade Office of the... adoption of grievance procedures. (a) Designation of responsible employee. A recipient, other than a small...) Adoption of grievance procedures. A recipient, other than a small recipient, shall adopt...

  6. 38 CFR 18.407 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... responsible employee and adoption of grievance procedures. 18.407 Section 18.407 Pensions, Bonuses, and... adoption of grievance procedures. (a) Designation of responsible employee. A recipient that employs fifteen... part. (b) Adoption of grievance procedures. A recipient that employs fifteen or more persons...

  7. 14 CFR 1251.106 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... adoption of grievance procedures. 1251.106 Section 1251.106 Aeronautics and Space NATIONAL AERONAUTICS AND... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee. A... comply with this part. (b) Adoption of grievance procedures. A recipient that employs 15 or more...

  8. 38 CFR 18.407 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... responsible employee and adoption of grievance procedures. 18.407 Section 18.407 Pensions, Bonuses, and... adoption of grievance procedures. (a) Designation of responsible employee. A recipient that employs fifteen... part. (b) Adoption of grievance procedures. A recipient that employs fifteen or more persons...

  9. 15 CFR 8b.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and adoption of grievance procedures. 8b.7 Section 8b.7 Commerce and Foreign Trade Office of the... adoption of grievance procedures. (a) Designation of responsible employee. A recipient, other than a small...) Adoption of grievance procedures. A recipient, other than a small recipient, shall adopt...

  10. Aerodynamic Characterization of a Modern Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Hall, Robert M.; Holland, Scott D.; Blevins, John A.

    2011-01-01

    A modern launch vehicle is by necessity an extremely integrated design. The accurate characterization of its aerodynamic characteristics is essential to determine design loads, to design flight control laws, and to establish performance. The NASA Ares Aerodynamics Panel has been responsible for technical planning, execution, and vetting of the aerodynamic characterization of the Ares I vehicle. An aerodynamics team supporting the Panel consists of wind tunnel engineers, computational engineers, database engineers, and other analysts that address topics such as uncertainty quantification. The team resides at three NASA centers: Langley Research Center, Marshall Space Flight Center, and Ames Research Center. The Panel has developed strategies to synergistically combine both the wind tunnel efforts and the computational efforts with the goal of validating the computations. Selected examples highlight key flow physics and, where possible, the fidelity of the comparisons between wind tunnel results and the computations. Lessons learned summarize what has been gleaned during the project and can be useful for other vehicle development projects.

  11. Design procedure for sizing a submerged-bed scrubber for airborne particulate removal

    SciTech Connect

    Ruecker, C.M.; Scott, P.A.

    1987-04-01

    Performance correlations to design and operate the submerged bed scrubber were developed for various applications. Structural design procedure outlined in this report focuses on off-gas scrubbing for HLW vitrification applications; however, the method is appropriate for other applications.

  12. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 1 publication covers configuration aerodynamics.

  13. Aerodynamic effects of flexibility in flapping wings

    PubMed Central

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P.

    2010-01-01

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re ≈ 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic

  14. An aerodynamic design study of a series of lifting bodies at angles of attack from 10 to 53 degrees at Mach numbers from 2.30 to 4.62

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.; Torres, Abel O.

    1992-01-01

    The aerodynamic characteristics in the transition from high to low angles of attack at supersonic speeds have been experimentally and theoretically studied for a series of lifting bodies with various upper and lower surface camber designs. The configurations under consideration have a 75-degree swept delta planform with a rounded nose. Data obtained indicate that changes in the camber design cause some distinct changes in the aerodynamic characteristics that shoud be taken into account in the selection of a lifting body shape. The flat bottom designs with upper surface camber are found to provide greater drag for retardation at high angles of attack but are considerably out of trim longitudinally. The flat top designs with lower surface camber provide less drag at high angles of attack but can be more easily trimmed. Calculated results are found to be in good agreement with the experimental data.

  15. 33 CFR 263.17 - Planning, design and construction procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Planning, design and construction..., DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS General § 263.17 Planning, design and construction... study. Studies will be conducted in accordance with the policies given in § 263.15 and the...

  16. 40 CFR 240.203-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... design. (b) Resource recovery in the form of heat utilization or direct recovery of materials should be... waters. (f) Facility design capacity should consider such items as waste quantity and characteristics, variations in waste generation, equipment downtime, and availability of alternate storage, processing,...

  17. 40 CFR 240.203-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... design. (b) Resource recovery in the form of heat utilization or direct recovery of materials should be... waters. (f) Facility design capacity should consider such items as waste quantity and characteristics, variations in waste generation, equipment downtime, and availability of alternate storage, processing,...

  18. 21 CFR 26.66 - Designation and listing procedures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26.66 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... apply with regard to the designation of conformity assessment bodies (CAB's) and the inclusion of such bodies in the list of CAB's in subpart B of this part: (a) The designating authority identified...

  19. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Design procedures for concrete....306 Design procedures for concrete block piers. (a) Frame piers less than 36 inches high. (1) Frame piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell...

  20. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Design procedures for concrete....306 Design procedures for concrete block piers. (a) Frame piers less than 36 inches high. (1) Frame piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell...

  1. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Design procedures for concrete....306 Design procedures for concrete block piers. (a) Frame piers less than 36 inches high. (1) Frame piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell...

  2. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Design procedures for concrete....306 Design procedures for concrete block piers. (a) Frame piers less than 36 inches high. (1) Frame piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell...

  3. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Design procedures for concrete....306 Design procedures for concrete block piers. (a) Frame piers less than 36 inches high. (1) Frame piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell...

  4. 34 CFR 106.8 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Designation of responsible employee and adoption of grievance procedures. 106.8 Section 106.8 Education Regulations of the Offices of the Department of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  5. 45 CFR 605.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Designation of responsible employee and adoption... adoption of grievance procedures. (a) Designation of responsible employee. A recipient that employs fifteen... part. (b) Adoption of grievance procedures. A recipient that employs fifteen or more persons...

  6. 18 CFR 1317.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Designation of responsible employee and adoption of grievance procedures. 1317.135 Section 1317.135 Conservation of Power and... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  7. 24 CFR 3.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Designation of responsible employee and adoption of grievance procedures. 3.135 Section 3.135 Housing and Urban Development Office of the... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  8. 24 CFR 3.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Designation of responsible employee and adoption of grievance procedures. 3.135 Section 3.135 Housing and Urban Development Office of the... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  9. 45 CFR 618.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Designation of responsible employee and adoption of grievance procedures. 618.135 Section 618.135 Public Welfare Regulations Relating to Public... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  10. 45 CFR 618.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Designation of responsible employee and adoption of grievance procedures. 618.135 Section 618.135 Public Welfare Regulations Relating to Public... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  11. 34 CFR 104.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Designation of responsible employee and adoption of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee. A... to comply with this part. (b) Adoption of grievance procedures. A recipient that employs fifteen...

  12. 18 CFR 1317.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Designation of responsible employee and adoption of grievance procedures. 1317.135 Section 1317.135 Conservation of Power and... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  13. 34 CFR 106.8 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Designation of responsible employee and adoption of grievance procedures. 106.8 Section 106.8 Education Regulations of the Offices of the Department of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  14. 34 CFR 104.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Designation of responsible employee and adoption of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee. A... to comply with this part. (b) Adoption of grievance procedures. A recipient that employs fifteen...

  15. 6 CFR 17.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Designation of responsible employee and adoption of grievance procedures. 17.135 Section 17.135 Domestic Security DEPARTMENT OF HOMELAND SECURITY... adoption of grievance procedures. (a) Designation of responsible employee. Each recipient shall...

  16. 45 CFR 1170.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Designation of responsible employee and adoption... Enforcement § 1170.53 Designation of responsible employee and adoption of grievance procedures. (a... one person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  17. 45 CFR 605.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Designation of responsible employee and adoption... adoption of grievance procedures. (a) Designation of responsible employee. A recipient that employs fifteen... part. (b) Adoption of grievance procedures. A recipient that employs fifteen or more persons...

  18. 32 CFR 196.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Designation of responsible employee and adoption of grievance procedures. 196.135 Section 196.135 National Defense Department of Defense (Continued... of responsible employee and adoption of grievance procedures. (a) Designation of responsible...

  19. 45 CFR 1170.53 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Designation of responsible employee and adoption... Enforcement § 1170.53 Designation of responsible employee and adoption of grievance procedures. (a... one person to coordinate its efforts to comply with this part. (b) Adoption of grievance procedures....

  20. 24 CFR 3.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Designation of responsible employee and adoption of grievance procedures. 3.135 Section 3.135 Housing and Urban Development Office of the... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  1. 34 CFR 106.8 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Designation of responsible employee and adoption of grievance procedures. 106.8 Section 106.8 Education Regulations of the Offices of the Department of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  2. 38 CFR 23.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Designation of responsible employee and adoption of grievance procedures. 23.135 Section 23.135 Pensions, Bonuses, and... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  3. 10 CFR 1042.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Designation of responsible employee and adoption of grievance procedures. 1042.135 Section 1042.135 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS... Introduction § 1042.135 Designation of responsible employee and adoption of grievance procedures....

  4. 18 CFR 1317.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Designation of responsible employee and adoption of grievance procedures. 1317.135 Section 1317.135 Conservation of Power and... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  5. 32 CFR 196.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Designation of responsible employee and adoption of grievance procedures. 196.135 Section 196.135 National Defense Department of Defense (Continued... of responsible employee and adoption of grievance procedures. (a) Designation of responsible...

  6. 34 CFR 104.7 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Designation of responsible employee and adoption of... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee. A... to comply with this part. (b) Adoption of grievance procedures. A recipient that employs fifteen...

  7. 24 CFR 3.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Designation of responsible employee and adoption of grievance procedures. 3.135 Section 3.135 Housing and Urban Development Office of the... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  8. 18 CFR 1317.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Designation of responsible employee and adoption of grievance procedures. 1317.135 Section 1317.135 Conservation of Power and... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee....

  9. 6 CFR 17.135 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 6 Domestic Security 1 2012-01-01 2012-01-01 false Designation of responsible employee and adoption of grievance procedures. 17.135 Section 17.135 Domestic Security DEPARTMENT OF HOMELAND SECURITY... adoption of grievance procedures. (a) Designation of responsible employee. Each recipient shall...

  10. 28 CFR 35.107 - Designation of responsible employee and adoption of grievance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Designation of responsible employee and adoption of grievance procedures. 35.107 Section 35.107 Judicial Administration DEPARTMENT OF JUSTICE... responsible employee and adoption of grievance procedures. (a) Designation of responsible employee. A...

  11. 6 CFR 25.6 - Procedures for designation of qualified anti-terrorism technologies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 6 Domestic Security 1 2012-01-01 2012-01-01 false Procedures for designation of qualified anti-terrorism technologies. 25.6 Section 25.6 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY REGULATIONS TO SUPPORT ANTI-TERRORISM BY FOSTERING EFFECTIVE TECHNOLOGIES § 25.6 Procedures for designation of qualified...

  12. 48 CFR 570.305 - Two-phase design-build selection procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Two-phase design-build... for Leasehold Interests in Real Property 570.305 Two-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if you use the two-phase...

  13. 13 CFR 108.1940 - Procedures for designation of additional Low-Income Geographic Areas

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Procedures for designation of additional Low-Income Geographic Areas 108.1940 Section 108.1940 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM Miscellaneous § 108.1940 Procedures for designation of additional...

  14. Nostril Aerodynamics of Scenting Animals

    NASA Astrophysics Data System (ADS)

    Settles, G. S.

    1997-11-01

    Dogs and other scenting animals detect airborne odors with extraordinary sensitivity. Aerodynamic sampling plays a key role, but the literature on olfaction contains little on the external aerodynamics thereof. To shed some light on this, the airflows generated by a scenting dog were visualized using the schlieren technique. It was seen that the dog stops panting in order to scent, since panting produces a turbulent jet which disturbs scent-bearing air currents. Inspiratory airflow enters the nostrils from straight ahead, while expiration is directed to the sides of the nose and downward, as was found elsewhere in the case of rats and rabbits. The musculature and geometry of the dog's nose thus modulates the airflow during scenting. The aerodynamics of a nostril which must act reversibly as both inlet and outlet is briefly discussed. The eventual practical goal of this preliminary work is to achieve a level of understanding of the aerodynamics of canine olfaction sufficient for the design of a mimicking device. (Research supported by the DARPA Unexploded Ordnance Detection and Neutralization Program.)

  15. Fatigue design procedure for the American SST prototype

    NASA Technical Reports Server (NTRS)

    Doty, R. J.

    1972-01-01

    For supersonic airline operations, significantly higher environmental temperature is the primary new factor affecting structural service life. Methods for incorporating the influence of temperature in detailed fatigue analyses are shown along with current test indications. Thermal effects investigated include real-time compared with short-time testing, long-time temperature exposure, and stress-temperature cycle phasing. A method is presented which allows designers and stress analyzers to check fatigue resistance of structural design details. A communicative rating system is presented which defines the relative fatigue quality of the detail so that the analyst can define cyclic-load capability of the design detail by entering constant-life charts for varying detail quality. If necessary then, this system allows the designer to determine ways to improve the fatigue quality for better life or to determine the operating stresses which will provide the required service life.

  16. 40 CFR 240.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... stumps, large timbers, furniture, and major appliances), digested and dewatered sludges from waste water treatment facilities, raw sewage sludges, and septic tank pumpings. (b) If the facility is designed...

  17. 40 CFR 240.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... stumps, large timbers, furniture, and major appliances), digested and dewatered sludges from waste water treatment facilities, raw sewage sludges, and septic tank pumpings. (b) If the facility is designed...

  18. 40 CFR 240.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... stumps, large timbers, furniture, and major appliances), digested and dewatered sludges from waste water treatment facilities, raw sewage sludges, and septic tank pumpings. (b) If the facility is designed...

  19. 40 CFR 240.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... stumps, large timbers, furniture, and major appliances), digested and dewatered sludges from waste water treatment facilities, raw sewage sludges, and septic tank pumpings. (b) If the facility is designed...

  20. 40 CFR 240.200-2 - Recommended procedures: Design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... stumps, large timbers, furniture, and major appliances), digested and dewatered sludges from waste water treatment facilities, raw sewage sludges, and septic tank pumpings. (b) If the facility is designed...

  1. Proposed design procedure for transmission shafting under fatigue loading

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1978-01-01

    A new standard for the design of transmission shafting is reported. Computed was the diameter of rotating solid steel shafts under combined cyclic bending and steady torsion is presented. The formula is based on an elliptical variation of endurance strength with torque exhibited by combined stress fatigue data. Fatigue factors are cited to correct specimen bending endurance strength data for use in the shaft formula. A design example illustrates how the method is to be applied.

  2. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 2 publication covers the design optimization and testing sessions.

  3. Aerodynamic analysis of Pegasus - Computations vs reality

    NASA Technical Reports Server (NTRS)

    Mendenhall, Michael R.; Lesieutre, Daniel J.; Whittaker, C. H.; Curry, Robert E.; Moulton, Bryan

    1993-01-01

    Pegasus, a three-stage, air-launched, winged space booster was developed to provide fast and efficient commercial launch services for small satellites. The aerodynamic design and analysis of Pegasus was conducted without benefit of wind tunnel tests using only computational aerodynamic and fluid dynamic methods. Flight test data from the first two operational flights of Pegasus are now available, and they provide an opportunity to validate the accuracy of the predicted pre-flight aerodynamic characteristics. Comparisons of measured and predicted flight characteristics are presented and discussed. Results show that the computational methods provide reasonable aerodynamic design information with acceptable margins. Post-flight analyses illustrate certain areas in which improvements are desired.

  4. Switchable and Tunable Aerodynamic Drag on Cylinders

    NASA Astrophysics Data System (ADS)

    Guttag, Mark; Lopez Jimenez, Francisco; Reis, Pedro

    2015-11-01

    We report results on the performance of Smart Morphable Surfaces (Smporhs) that can be mounted onto cylindrical structures to actively reduce their aerodynamic drag. Our system comprises of an elastomeric thin shell with a series of carefully designed subsurface cavities that, once depressurized, lead to a dramatic deformation of the surface topography, on demand. Our design is inspired by the morphology of the giant cactus (Carnegiea gigantea) which possesses an array of axial grooves, which are thought to help reduce aerodynamic drag, thereby enhancing the structural robustness of the plant under wind loading. We perform systematic wind tunnel tests on cylinders covered with our Smorphs and characterize their aerodynamic performance. The switchable and tunable nature of our system offers substantial advantages for aerodynamic performance when compared to static topographies, due to their operation over a wider range of flow conditions.

  5. Switchable and Tunable Aerodynamic Drag on Cylinders

    NASA Astrophysics Data System (ADS)

    Guttag, Mark; Lopéz Jiménez, Francisco; Upadhyaya, Priyank; Kumar, Shanmugam; Reis, Pedro

    We report results on the performance of Smart Morphable Surfaces (Smporhs) that can be mounted onto cylindrical structures to actively reduce their aerodynamic drag. Our system comprises of an elastomeric thin shell with a series of carefully designed subsurface cavities that, once depressurized, lead to a dramatic deformation of the surface topography, on demand. Our design is inspired by the morphology of the giant cactus (Carnegiea gigantea) which possesses an array of axial grooves, thought to help reduce aerodynamic drag, thereby enhancing the structural robustness of the plant under wind loading. We perform systematic wind tunnel tests on cylinders covered with our Smorphs and characterize their aerodynamic performance. The switchable and tunable nature of our system offers substantial advantages for aerodynamic performance when compared to static topographies, due to their operation over a wider range of flow conditions.

  6. X-34 Vehicle Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Brauckmann, Gregory J.

    1998-01-01

    The X-34, being designed and built by the Orbital Sciences Corporation, is an unmanned sub-orbital vehicle designed to be used as a flying test bed to demonstrate key vehicle and operational technologies applicable to future reusable launch vehicles. The X-34 will be air-launched from an L-1011 carrier aircraft at approximately Mach 0.7 and 38,000 feet altitude, where an onboard engine will accelerate the vehicle to speeds above Mach 7 and altitudes to 250,000 feet. An unpowered entry will follow, including an autonomous landing. The X-34 will demonstrate the ability to fly through inclement weather, land horizontally at a designated site, and have a rapid turn-around capability. A series of wind tunnel tests on scaled models was conducted in four facilities at the NASA Langley Research Center to determine the aerodynamic characteristics of the X-34. Analysis of these test results revealed that longitudinal trim could be achieved throughout the design trajectory. The maximum elevon deflection required to trim was only half of that available, leaving a margin for gust alleviation and aerodynamic coefficient uncertainty. Directional control can be achieved aerodynamically except at combined high Mach numbers and high angles of attack, where reaction control jets must be used. The X-34 landing speed, between 184 and 206 knots, is within the capabilities of the gear and tires, and the vehicle has sufficient rudder authority to control the required 30-knot crosswind.

  7. Control of helicopter rotorblade aerodynamics

    NASA Technical Reports Server (NTRS)

    Fabunmi, James A.

    1991-01-01

    The results of a feasibility study of a method for controlling the aerodynamics of helicopter rotorblades using stacks of piezoelectric ceramic plates are presented. A resonant mechanism is proposed for the amplification of the displacements produced by the stack. This motion is then converted into linear displacement for the actuation of the servoflap of the blades. A design which emulates the actuation of the servoflap on the Kaman SH-2F is used to demonstrate the fact that such a system can be designed to produce the necessary forces and velocities needed to control the aerodynamics of the rotorblades of such a helicopter. Estimates of the electrical power requirements are also presented. A Small Business Innovation Research (SBIR) Phase 2 Program is suggested, whereby a bench-top prototype of the device can be built and tested. A collaborative effort between AEDAR Corporation and Kaman Aerospace Corporation is anticipated for future effort on this project.

  8. Preliminary design procedure for insulated structures subjected to transient heating

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.

    1979-01-01

    Minimum-mass designs were obtained for insulated structural panels loaded by a general set of inplane forces and a time dependent temperature. Temperature and stress histories in the structure are given by closed-form solutions, and optimization of the insulation and structural thicknesses is performed by nonlinear mathematical programming techniques. Design calculations are described to evaluate the structural efficiency of eight materials under combined heating and mechanical loads: graphite/polyimide, graphite/epoxy, boron/aluminum, titanium, aluminum, Rene 41, carbon/carbon, and Lockalloy. The effect on design mass of intensity and duration of heating were assessed. Results indicate that an optimum structure may have a temperature response well below the recommended allowable temperature for the material.

  9. Students' Design of a Biometric Procedure in Upper Secondary School

    ERIC Educational Resources Information Center

    Marzin, Patricia; de Vries, Erica

    2013-01-01

    Making the connection between science and technology might be important for students to learn to identify and solve problems and to acquire scientific knowledge and skills. The research reported in this article concerned the development of a design situation in a science classroom and the study of students performing in this situation. More…

  10. 17 CFR 38.3 - Procedures for designation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...)(1)(ii)(A) through (E) raise issues that are novel, or for which compliance with a designation... incomplete; (ii) Fails in form or substance to meet the requirements of this part; (iii) Raises novel or... fails to meet the requirements of this part, the novel or complex issues that require additional...

  11. Uncertainty in Computational Aerodynamics

    NASA Technical Reports Server (NTRS)

    Luckring, J. M.; Hemsch, M. J.; Morrison, J. H.

    2003-01-01

    An approach is presented to treat computational aerodynamics as a process, subject to the fundamental quality assurance principles of process control and process improvement. We consider several aspects affecting uncertainty for the computational aerodynamic process and present a set of stages to determine the level of management required to meet risk assumptions desired by the customer of the predictions.

  12. Computation of dragonfly aerodynamics

    NASA Astrophysics Data System (ADS)

    Gustafson, Karl; Leben, Robert

    1991-04-01

    Dragonflies are seen to hover and dart, seemingly at will and in remarkably nimble fashion, with great bursts of speed and effectively discontinuous changes of direction. In their short lives, their gossamer flight provides us with glimpses of an aerodynamics of almost extraterrestrial quality. Here we present the first computer simulations of such aerodynamics.

  13. 1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in area of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodyamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executive summaries for all the Aerodynamic Performance technology areas.

  14. Aerodynamic characteristics at Mach numbers from 0.33 to 1.20 of a wing-body design concept for a hypersonic research airplane

    NASA Technical Reports Server (NTRS)

    Dillon, J. L.; Pittman, J. L.

    1977-01-01

    An experimental investigation of the static aerodynamic characteristics of a model of one design concept for the proposed National Hypersonic Flight Research Facility was conducted in the Langley 8 foot transonic pressure tunnel. The experiment consisted of configuration buildup from the basic body by adding a wing, center vertical tail, and a three module or six module scramjet engine. The freestream test Mach numbers were 0.33, 0.80, 0.90, 0.95, 0.98, 1.10, and 1.20 at Reynolds numbers per meter ranging from 4.8 x 1 million to 10.4 x 1 million. The test angle of attack range was approximately -4 deg to 22 deg at constant angles of sideslip of 0 deg and 4 deg; the angle of sideslip ranged from about -6 deg to 6 deg at constant angles of attack of 0 deg and 17 deg. The elevons were deflected 0 deg, -10 deg, and -20 deg with rudder deflections of 0 deg and 15.6 deg.

  15. Advancement of proprotor technology. Task 1: Design study summary. [aerodynamic concept of minimum size tilt proprotor research aircraft

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A tilt-proprotor proof-of-concept aircraft design study has been conducted. The results are presented. The ojective of the contract is to advance the state of proprotor technology through design studies and full-scale wind-tunnel tests. The specific objective is to conduct preliminary design studies to define a minimum-size tilt-proprotor research aircraft that can perform proof-of-concept flight research. The aircraft that results from these studies is a twin-engine, high-wing aircraft with 25-foot, three-bladed tilt proprotors mounted on pylons at the wingtips. Each pylon houses a Pratt and Whitney PT6C-40 engine with a takeoff rating of 1150 horsepower. Empty weight is estimated at 6876 pounds. The normal gross weight is 9500 pounds, and the maximum gross weight is 12,400 pounds.

  16. A design procedure for fan inflow control structures

    NASA Technical Reports Server (NTRS)

    Gedge, M. R.

    1980-01-01

    Significant differences exist in the noise generated by engine in flight and engines operating on the test stand. It was observed that these differences can be reduced by use of an inflow control structure (ICS) in the static test configuration. The results of the second phase of a three phase program are described and the results of a test program conducted to assess and modify various theoretical models, leading to the development of an ICS design system is summarized.

  17. High-loading, 1800 ft/sec tip speed transonic compressor fan stage. 1: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Morris, A. L.; Halle, J. E.; Kennedy, E. E.

    1972-01-01

    A single stage fan with a tip speed of 1800 ft/sec (548.6m/sec) and hub/tip ratio of 0.5 was designed to produce a pressure ratio of 2.285:1 with an adiabatic efficiency of 84.0%. The design flow per inlet annulus area is 38.7 lbm/sq ft-sec (188.9KG/sqm-sec). Rotor blades have modified multiple-circular-arc and precompression airfoil sections. The stator vanes have multiple-circular-arc airfoil sections.

  18. Optimum Design of High Speed Prop-Rotors

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi

    1992-01-01

    The objective of this research is to develop optimization procedures to provide design trends in high speed prop-rotors. The necessary disciplinary couplings are all considered within a closed loop optimization process. The procedures involve the consideration of blade aeroelastic, aerodynamic performance, structural and dynamic design requirements. Further, since the design involves consideration of several different objectives, multiobjective function formulation techniques are developed.

  19. Aerodynamic shape optimization of a HSCT type configuration with improved surface definition

    NASA Technical Reports Server (NTRS)

    Thomas, Almuttil M.; Tiwari, Surendra N.

    1994-01-01

    Two distinct parametrization procedures of generating free-form surfaces to represent aerospace vehicles are presented. The first procedure is the representation using spline functions such as nonuniform rational b-splines (NURBS) and the second is a novel (geometrical) parametrization using solutions to a suitably chosen partial differential equation. The main idea is to develop a surface which is more versatile and can be used in an optimization process. Unstructured volume grid is generated by an advancing front algorithm and solutions obtained using an Euler solver. Grid sensitivity with respect to surface design parameters and aerodynamic sensitivity coefficients based on potential flow is obtained using an automatic differentiator precompiler software tool. Aerodynamic shape optimization of a complete aircraft with twenty four design variables is performed. High speed civil transport aircraft (HSCT) configurations are targeted to demonstrate the process.

  20. A consistent design procedure for supercritical airfoils in free air and a wind tunnel

    NASA Technical Reports Server (NTRS)

    Shankar, V.; Malmuth, N. D.; Cole, J. D.

    1979-01-01

    A computational inverse procedure for transonic airfoils in which shapes are determined supporting prescribed pressure distributions is presented. The method uses the small disturbance equation and a consistent analysis-design differencing procedure at the airfoil surface. This avoids the intermediate analysis-design-analysis iterations. The effect of any openness at the trailing edge is taken onto account by adding an effective source term in the far field. The final results from a systematic expansion procedure which models the far field for solid, ideal slotted, and free jet tunnel walls are presented along with some design results for the associated boundary conditions and those for a free flight.

  1. 1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    McMillin, S. Naomi (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

  2. 1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    McMillin, S. Naomi (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry HighSpeed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of. Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

  3. Aerodynamic design of a midsized vertical-axis wind turbine using natural laminar-flow blade elements

    SciTech Connect

    Klimas, P.C.; Berg, D.E.

    1983-01-01

    Natural laminar-flow (NLF) airfoils are those which can achieve significant extents of laminar flow (greater than or equal to 30% chord) solely through favorable pressure gradients. Studies have shown that vertical-axis wind turbines (VAWTs) using NLF sections as blade elements have the potential of producing energy at a significantly lower cost (approx. =20%) than turbines of current design. Sandia National Laboratories (SNL) is now in the process of procuring a blade set for its 17-m-diameter research turbine which will use NLF sections as blade elements. This paper describes the design of this blade set. The blade set design began with the definition of a family of three approximately 50% chord NLF sections (15, 18, and 21% t/c). These definitions involved numerically establishing airfoil contours giving section characteristics anticipated to be favorable in the VAWT context and then screening these using a VAWT performance model. Field tests of the 15 and 18% t/c sections as elements on the SNL 5-m diameter research turbine were used to validate the predicted element performance and to establish the fact that laminar flow could be sustained in the VAWT environment. A static wind tunnel test series involving the three NLF sections was conducted in order to provide accurate late- and post-stall characteristics upon which to base the midsized design. These efforts resulted in a blade set design which used both the NACA 0015 and 18% t/c NLF sections. Installation and test of this blade set on the SNL 17-m diameter research turbine has been scheduled to begine during the fall of 1983.

  4. Inverse airfoil design procedure using a multigrid Navier-Stokes method

    NASA Technical Reports Server (NTRS)

    Malone, J. B.; Swanson, R. C.

    1991-01-01

    The Modified Garabedian McFadden (MGM) design procedure was incorporated into an existing 2-D multigrid Navier-Stokes airfoil analysis method. The resulting design method is an iterative procedure based on a residual correction algorithm and permits the automated design of airfoil sections with prescribed surface pressure distributions. The new design method, Multigrid Modified Garabedian McFadden (MG-MGM), is demonstrated for several different transonic pressure distributions obtained from both symmetric and cambered airfoil shapes. The airfoil profiles generated with the MG-MGM code are compared to the original configurations to assess the capabilities of the inverse design method.

  5. An annotated summary of the Information Model Design Procedure (IMDP)

    SciTech Connect

    Becker, S.D.

    1994-05-01

    This presentation documents the essential elements of the IMDP as applied at Sandia National Laboratories/New Mexico. The IMDP is an adaptation of the Natural-Language Information Analysis Methodology (NIAM) of G. M. Nijssen. The underlying purpose of both of these methodologies is to provide a formal, reproducible, and verifiable approach to specifying the information requirements of an information system. The IMDP spans the specification process from initial scoping; through verbalization of problem-domain facts, specification of constraints, and subtype analysis; and finally to application of a formal algorithm for developing a fifth-normal-form relational database design.

  6. Low-speed aerodynamic characteristics of a 13-percent-thick airfoil section designed for general aviation applications

    NASA Technical Reports Server (NTRS)

    Mcghee, R. J.; Beasley, W. D.; Somers, D. M.

    1975-01-01

    Wind-tunnel tests were conducted to determine the low-speed section characteristics of a 13 percent-thick airfoil designed for general aviation applications. The results were compared with NACA 12 percent-thick sections and with the 17 percent-thick NASA airfoil. The tests were conducted ovar a Mach number range from 0.10 to 0.35. Chord Reynolds numbers varied from about 2,000,000 to 9,000,000.

  7. 46 CFR 164.019-9 - Procedure for acceptance of revisions of design, process, or materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) The manufacturer shall not change the design, material, manufacturing process, or construction of a... requests for acceptance of revisions in design, material, manufacturing process, or construction of a non... 46 Shipping 6 2010-10-01 2010-10-01 false Procedure for acceptance of revisions of design,...

  8. 46 CFR 164.019-9 - Procedure for acceptance of revisions of design, process, or materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The manufacturer shall not change the design, material, manufacturing process, or construction of a... requests for acceptance of revisions in design, material, manufacturing process, or construction of a non... 46 Shipping 6 2012-10-01 2012-10-01 false Procedure for acceptance of revisions of design,...

  9. 46 CFR 164.019-9 - Procedure for acceptance of revisions of design, process, or materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The manufacturer shall not change the design, material, manufacturing process, or construction of a... requests for acceptance of revisions in design, material, manufacturing process, or construction of a non... 46 Shipping 6 2013-10-01 2013-10-01 false Procedure for acceptance of revisions of design,...

  10. 46 CFR 164.019-9 - Procedure for acceptance of revisions of design, process, or materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) The manufacturer shall not change the design, material, manufacturing process, or construction of a... requests for acceptance of revisions in design, material, manufacturing process, or construction of a non... 46 Shipping 6 2011-10-01 2011-10-01 false Procedure for acceptance of revisions of design,...

  11. 46 CFR 164.019-9 - Procedure for acceptance of revisions of design, process, or materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The manufacturer shall not change the design, material, manufacturing process, or construction of a... requests for acceptance of revisions in design, material, manufacturing process, or construction of a non... 46 Shipping 6 2014-10-01 2014-10-01 false Procedure for acceptance of revisions of design,...

  12. Viking entry aerodynamics and heating

    NASA Technical Reports Server (NTRS)

    Polutchko, R. J.

    1974-01-01

    The characteristics of the Mars entry including the mission sequence of events and associated spacecraft weights are described along with the Viking spacecraft. Test data are presented for the aerodynamic characteristics of the entry vehicle showing trimmed alpha, drag coefficient, and trimmed lift to drag ratio versus Mach number; the damping characteristics of the entry configuration; the angle of attack time history of Viking entries; stagnation heating and pressure time histories; and the aeroshell heating distribution as obtained in tests run in a shock tunnel for various gases. Flight tests which demonstrate the aerodynamic separation of the full-scale aeroshell and the flying qualities of the entry configuration in an uncontrolled mode are documented. Design values selected for the heat protection system based on the test data and analysis performed are presented.

  13. 21 CFR 3.5 - Procedures for identifying the designated agency component.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Procedures for identifying the designated agency component. 3.5 Section 3.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PRODUCT JURISDICTION Assignment of Agency Component for Review of Premarket Applications § 3.5 Procedures for identifying...

  14. The Development of a Procedure for the Design of Competency Based Modular Instructional Programs. Final Report.

    ERIC Educational Resources Information Center

    Schurter, William J.

    A project was designed to develop a curriculum model based on salient, sequenced occupational tasks. After an extensive literature review and staff discussions, a modified Q-Sort procedure was formulated to select and sequence tasks. The procedure made it possible to readily utilize a catalogue of tasks compiled by the Vocational-Technical…

  15. 47 CFR 68.418 - Procedure; designation of agents for service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Procedure; designation of agents for service. 68.418 Section 68.418 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Complaint Procedures §...

  16. 47 CFR 68.418 - Procedure; designation of agents for service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Procedure; designation of agents for service. 68.418 Section 68.418 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Complaint Procedures §...

  17. 6 CFR 25.6 - Procedures for designation of qualified anti-terrorism technologies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-terrorism technologies. 25.6 Section 25.6 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY REGULATIONS TO SUPPORT ANTI-TERRORISM BY FOSTERING EFFECTIVE TECHNOLOGIES § 25.6 Procedures for designation of qualified anti-terrorism technologies. (a) Application Procedure. Any person, firm or...

  18. 47 CFR 7.18 - Procedure; designation of agents for service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Procedure; designation of agents for service. 7.18 Section 7.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL ACCESS TO VOICEMAIL AND INTERACTIVE MENU SERVICES AND EQUIPMENT BY PEOPLE WITH DISABILITIES Enforcement § 7.18 Procedure;...

  19. 47 CFR 7.18 - Procedure; designation of agents for service.

    Code of Federal Regulations, 2014 CFR

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